NULL Value in Oracle Database | Oracle Tutorials for Beginners NULL Value in Oracle Database NULL Value in Oracle SQL NULL Value in SQL NULL Value in Oracle Database Oracle Tutorials for Beginners Oracle Tutorials for Beginners Oracle PL/SQL Tutorials for Beginners Oracle PL/SQL Tutorials for Beginners Oracle PL/SQL Tutorials for Beginners how to select null values in oracle oracle compare null values in where clause null=null in oracle how to handle null in case statement in oracle how to check null value in oracle stored procedure oracle nvl null value in oracle query how to check empty column value in oracle how to select null values in oracle oracle is null vs = null oracle nvl oracle is not null oracle decode oracle isnull oracle case when null select null from table in oracle oracle compare null values in where clause oracle select null how to check empty column value in oracle oracle sql not null or empty oracle is not null how to handle null in case statement in oracle oracle isnull oracle nvl
Views: 407 Oracle PL/SQL World
In the last video we created our first table, but I want to give SQL Server some extra information so the database knows more about each of the columns. The first thing is to establish the primary key. To do this all we do is add PRIMARY KEY after the column we want to be the primary key. Simple enough. When we add a constraint right after the column like this, it is often called a column attribute. CREATE TABLE Animals( ID INT PRIMARY KEY, Name VARCHAR(50), Species VARCHAR(50) ); Additionally, if you are using an ID column, it is best to have it labeled as the IDENTITY column. That way, SQL Server will automatically increment the number. CREATE TABLE Animals( ID INT PRIMARY KEY IDENTITY, Name VARCHAR(50), Species VARCHAR(50) ); The other attributes we've discussed in this series are NOT NULL and UNIQUE. We can make the name NOT NULL and the species NOT NULL. We don't have a good column for UNIQUE, so let's add one: CREATE TABLE Animals( ID INT PRIMARY KEY IDENTITY, Name VARCHAR(50) NOT NULL, Species VARCHAR(50) NOT NULL, ContactEmail VARCHAR(50) NOT NULL UNIUQE ); You can see that it is very easy to add multiple column attributes to a column. Just separate them by spaces. The order does not matter. Also, when you say primary key the column is automatically NOT NULL and UNIQUE. There are other attributes you can use including DEFAULT, FOREIGN KEY, and SPARSE. DEFAULT will give a value for a column if you do not put anything in yourself. Foreign keys are used to reference other columns. SPARSE is an attribute we haven't discussed. You can use SPARSE if most of the rows are going to have a NULL for a column and it saves storage space, but we will worry about that in another video. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 3787 Caleb Curry
** For Online Training Registration: https://goo.gl/r6kJbB ? Call: +91-8179191999 ? Visit Our Website for Classroom Training: https://nareshit.in/sql-server-training/ ? For Online Training: https://nareshit.com/course/sql-server-dba-online-training/ #sqlserver #server #programming #course #Tutorials #Training #Videos -------------------------- ? About NareshIT: "Naresh IT is having 14+ years of experience in software training industry and the best Software Training Institute for online training, classroom training, weekend training, corporate training of Hadoop, Salesforce, AWS, DevOps, Spark, Data Science, Python, Tableau, RPA ,Java, C#.NET, ASP.NET, Oracle, Testing Tools, Silver light, Linq, SQL Server, Selenium, Android, iPhone, C Language, C++, PHP and Digital Marketing in USA,Hyderabad, Chennai and Vijayawada,Bangalore India which provides online training across all the locations -------------------------- ? Our Online Training Features: 1.Training with Real-Time Experts 2.Industry Specific Scenario’s 3.Flexible Timings 4.Soft Copy of Material 5. Share Videos of each and every session. -------------------------- Please write back to us at [email protected]/[email protected] or Call us at USA: +1404-232-9879 or India: +918179191999 ** Check The Below Links** ? For Course Reg: https://goo.gl/r6kJbB ? Subscribe to Our Channel: https://goo.gl/q9ozyG ? Circle us on G+: https://plus.google.com/NareshIT ? Like us on Facebook: https://www.facebook.com/NareshIT ? Follow us on Twitter: https://twitter.com/nareshitech ? Follow us on Linkedin: https://in.linkedin.com/company/nares... ? Follow us on Instagram: https://www.instagram.com/nareshitech/
Views: 3262 Naresh i Technologies
As I believe I've mentioned in an earlier video, a constraint is basically a rule we can put in our database that prevents someone from putting the wrong data in. It protects our relationships and data integrity. Because the goal of these constraints are to protect our data integrity, you may hear them called integrity constraints. There are many integrity constraints we are going to talk about: NOT NULL UNIQUE PRIMARY KEY FOREIGN KRY CHECK There is also the DEFAULT attribute. These are all keywords we can add to our columns that will change the way the database works with our data and also prevents incorrect data. NOT NULL is a constraint you can put on a column that prevents nulls. A null is the absence of a value. When we say null, we are saying that every single row has to have a value for this column. UNIQUE is a constraint that makes every row have a unique value for this column. Now note, this does not require values to be put it, and it will allow multiple rows to be null. Next, we are going to talk about primary keys. What qualifies a column as a candidate key? First, not a single row should have a null for that column. Second, every row must be unique. The primary key constraint is essentially a combination of the NOT NULL constraint and the UNIQUE constraint. The foreign key constraint sets the requirement that any value in this column for any row must match a row in another column. Check constraints allow us to be more strict with what data is allowed in our database. NOT NULL and UNIQUE give some level of restriction, but what if we want something more specific? For example, what if we only want values between 0 and 100? That is where check constraints come in. When using check constraints, you give a boolean expression. A boolean expression is something that can be evaluated to true or false. It will only insert the row if the value you try to put into the row makes the expression evaluate to true. So if you put in a value too great or small, the expression will be false and the data is not allowed to be entered. The default constraint is a value you can give a column, and if for any reason when the row is created in the table a value is not provided, the default value will be given. So for example, we could have a bank account table where the balance defaults to 0. How do you actually implement these constraints when you are creating a table? In the next video we are going to be adding these to our users table. Please be sure to subscribe! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon: http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 18034 Caleb Curry
NOT NULL, DEFAULT, CHECK Constraints (Domain Integrity) in SQL Server Check my blog for more on Constraints and related sample SQL Queries: http://sqlwithmanoj.com/2010/11/23/integrity-constraints/ Check the whole "SQL Server Basics" series here: https://www.youtube.com/playlist?list=PLU9JMEzjCv14f3cWDhubPaddxRvx1reKR Check my SQL blog at: http://sqlwithmanoj.com/ Check my SQL FB Page at: https://www.facebook.com/sqlwithmanoj
Views: 13840 SQL with Manoj
Constraint In Oracle PL SQL oracle tutorial for beginners A) UNIQUE CONSTRAINT : A unique constraint is uniquely defines a record. Its value is not repeated. It can be null. B)NOT NULL CONSTRAINT: Not null constraint restrict from inserting null values. If we want some columns does not take null values then we can use this constraint. C)CHECK CONSTRAINT: A check constraint allows you to specify a condition on particular column in a table. we can add our custom logical conditions. CREATE TABLE TEST2 ( ID VARCHAR2(10) UNIQUE, NAME VARCHAR2(50), DEPT VARCHAR2(10) NOT NULL, AGE NUMBER(10), CHECK (AGE BETWEEN 18 and 60) ); #techquerypond https://techquerypond.wordpress.com https://techquerypond.com https://twitter.com/techquerypond
Views: 173 Tech Query Pond
SQL SELECT statement is used to fetch the data from a database table which returns data in the form of result table. These result tables are called result-sets. The LIKE operator is used in a WHERE clause to search for a specified pattern in a column. In SQL, wildcard characters are used with the SQL LIKE operator. SQL wildcards are used to search for data within a table. With SQL, the wildcards are: Wildcard Description % A substitute for zero or more characters _ A substitute for a single character [charlist] Sets and ranges of characters to match [^charlist] or [!charlist] Matches only a character NOT specified within the brackets Check out our website: http://www.telusko.com Follow Telusko on Twitter: https://twitter.com/navinreddy20 Follow on Facebook: Telusko : https://www.facebook.com/teluskolearnings Navin Reddy : https://www.facebook.com/navintelusko Follow Navin Reddy on Instagram: https://www.instagram.com/navinreddy20 Subscribe to our other channel: Navin Reddy : https://www.youtube.com/channel/UCxmkk8bMSOF-UBF43z-pdGQ?sub_confirmation=1 Telusko Hindi : https://www.youtube.com/channel/UCitzw4ROeTVGRRLnCPws-cw?sub_confirmation=1
Views: 16571 Telusko
This video tutorial contains information about constraints in an RDBMS system, along with the inline and out of line constraint declaration type available in Oracle SQL. The video also demonstrates examples with check and not null constraint in Oracle SQL.
Views: 797 Kishan Mashru
How are NULL values treated while Sorting Data https://www.youtube.com/channel/UCnBpiBIOtRgMsk4G7Ri1jbQ
Views: 538 Oracle SQL
Hi Friends, In this in this session we are going to learn the differences between primary key and unique key This is one of the most frequently asked sql server interview questions. Before we discuss the difference between primary key and unique key, let's see what a primary key is and what a unique key is. Primary Key: Primary key is a key which uniquely identifies each row/record in the table. This implies if you have a primary key on a table, you can identify each and every row in that table uniquely using primary key. Unique Key: Unique key constraint enforces the uniqueness on the columns in which it is defined. That is Unique key will make sure only unique values are allowed in the columns in which it is defined. Similarities: Both Primary key and unique Key enforces uniqueness on the columns on which they are defined. • Primary key and unique Key columns allow only unique values. • Primary key and unique Key columns will avoid duplicates • Both Primary key and unique Key columns uniquely identifies each row/record in the table Differences: PRIMARY KEY UNIQUE KEY Primary Key Does not allow duplicates Unique key allows only one NULL A table can have only 1 Primary Key A table can have multiple Unique Keys By default Primary Key creates a Unique Clustered Index on the table By default Unique Key creates a Unique Non-Clustered Index on the table. I hope this session is clear and i hope this knowldge should help you in interviews. Please share your valuable comments & sugesstions. Also, subscriber to my channel for more sql server interview questions and answers. Bye bye & Have a good day.
Views: 37237 TheSSScreations
DISTINCT & UNIQUE Keyword in Oracle | Oracle Tutorials for Beginners DISTINCT Keyword in Oracle DISTINCT Clause in Oracle UNIQUE Keyword in Oracle UNIQUE Clause in Oracle Oracle Tutorials for Beginners Oracle Tutorials for Beginners select distinct * sql distinct multiple columns sql distinct count select distinct on one column with multiple columns returned select distinct mysql sql count distinct multiple columns oracle distinct count sql distinct group by sql count distinct two columns select distinct on one column with multiple columns returned select distinct on one column with multiple columns returned oracle sql select unique values from multiple columns select distinct multiple columns mysql select distinct all columns sql count distinct multiple columns group by sql select distinct multiple columns group by select distinct oracle select distinct rows sql select distinct multiple columns select distinct on one column select count distinct select unique mysql how to select unique records in oracle without using distinct sql select distinct values and count of each Oracle Tutorials for Beginners Oracle Tutorials for Beginners Oracle Tutorials for Beginners Oracle Tutorials for Beginners
Views: 399 Oracle PL/SQL World
by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How To Add Primary Key Constraint To a Table.إضافة قيد المفتاح الرئيسى للجدول Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint
Views: 54158 محمد الدسوقى
This video explains how to drop primary key,not null,unique,default and check constraints with or without constraint name in a table link to HOW to add constraint while creating table: https:// https://www.youtube.com/watch?v=dh_UKs-LnK8 link to how to add new columns with constraints : https://www.youtube.com/watch?v=UNAatxnnwB8 link to how to add constraints to existing column https://www.youtube.com/watch?v=02_fXRQpwSc how to drop all constraints on the table: https://www.youtube.com/watch?v=CM7FPqIr6gc subscribe - https://www.youtube.com/channel/UCNl7...
Views: 1803 kwl zerotwonine
Oracle DB - Primary Foreign Unique Not Null Check Composite Keys Table Level and Column Level
Views: 2649 Adel Sabour
Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints. Using dataset in asp.net
Views: 443 Engineer's Community Guide
In this video we will learn 1. What is unique key constraint 2. When do you use unique key constraint over primary key constraint 3. Difference between unique key constraint and primary key constraint Text version of the video http://csharp-video-tutorials.blogspot.com/2012/08/unique-key-constraint-part-9.html Slides http://csharp-video-tutorials.blogspot.com/2013/08/part-9-unique-key-constraint.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists
Views: 278675 kudvenkat
This Video Tutorial Will Describe how to get DISTINCT OR unique values or data from a table in oracle 12C version. This command will also work on other versions of database like Oracle 11g Database, Oracle 10g Database, Oracle 9i Database, Oracle 8i Database, Oracle 8 Database and so on. Whenever you create a new table in oracle, sometimes you just insert the duplicate data or sometimes you need to get only some columns of data which are duplicate but the row is unique. In that case, you need this DISTINCT clause. Full Syntax will be given in this video tutorial about how to get unique records from oracle database table. Along with the live example to get DISTINCT records. All the keywords, format, mandatory clauses etc are described in this video.
Views: 770 Oracle 12c Tutorials for Beginners
This is a free video tutorial by Kishan mashru on unique constraint in Oracle SQL, the video firstly explains what unique constraint is and how it can be used along with its various limitations, then the video gives perfect examples to understand how to create a unique key at the column level or inline, or at the table level i.e out of line. The video gives a demonstration on ALTER TABLE ADD CONSTRAINT and ALTER TABLE DROP CONSTRAINT statements also.
Views: 917 Kishan Mashru
SQL Server / TSQL Tutorial Scenario: If you have noticed the insert statement, In First Record I have put both Null values for FirstName and Last Name. In 2nd record I used the value 'Aamir' for first name and Null for Last Name. In 3rd record vice versa of 2nd record. From here what we understand that the unique constraint is working on both column values. As long as the combined value from both columns is unique, it is going to let us insert even one of them is null. Link to scripts used in SQL Server / TSQL Tutorial Video http://www.techbrothersit.com/2016/05/how-to-create-unique-constraint-on.html Check out our website for Different SQL Server, MSBI tutorials and interview questions such as SQL Server Reporting Services(SSRS) Tutorial SQL Server Integration Services(SSIS) Tutorial SQL Server DBA Tutorial SQL Server / TSQL Tutorial ( Beginner to Advance) http://www.techbrothersit.com/
Views: 2111 TechBrothersIT
Welcome everyone! Something you need to consider when you are creating foreign keys is what happens if you delete the parent? As a reminder, the parent is the row that has the value you are referencing in the row that has a foreign key. Why is this something important to consider? It's important because foreign keys need to protect us from two primary things, unacceptable INSERT statements, and unacceptable DELETE statements. Let's see what happens when we try to insert incorrect data into the table with the foreign key: INSERT INTO projects VALUES (1, 'Update website homepage', 'CalebCurry') The response tells us plainly that there is no such user in the users table. So this works correctly. Deleting data on the other hand works a bit differently because the database does not know what you want to do with the child row when you delete the parent from the parent table. By default, we will get an error message that prevents the parent from being deleted, but there are some other options. How do we configure this? This is where the ON DELETE statement comes in. We add the keywords ON DELETE right after the foreign key and then we can give it the option of CASCADE or SET NULL. CASCADE means that if we delete the parent, we are also going to delete the child. In our situation what that means is that if somebody creates a project in our project table and then that persons account gets deleted, all of the projects he owns will also be deleted. CASCADE: CREATE TABLE projects( project_id NUMBER, Project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (project_id), CONSTRAINT projects_users_fk FOREIGN KEY (creator) REFERENCES users (username) ON DELETE CASCADE ) SET NULL will take the value in the child table and get rid of it. What you are left with is NULL. This means that we have an orphaned child. The first thought you might have is that it is a bad thing to have an orphaned child, but in databases that is not always so. In our application if we had it set to SET NULL, when a user account gets deleted the projects would remain in existence they would just lack a creator. This might be a good thing if you are concerned about the long term survival of a project, this might be the route you want to go. It ultimately depends on the application purpose. If you don't like CASCADE or SET NULL, you can leave the entire ON DELETE statement and just have Oracle throw an error when a parent is deleted. As for us, we are going to use ON DELETE CASCADE. We need to use this with extreme caution. If you are not careful, someday you will run a delete a row and that will cascade through you database deleting a bunch of stuff you didn't want to delete. Stuff happens, so make sure you back up your database every once in eternity. Now, in the last video we started with a database design that had three tables. We've only created two in this video. In the next video we are going to create the next one, which is a little special. Then we'll finish things up by adding some indexes. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 13337 Caleb Curry
In this video you will learn about Not Null Constraint in PL/SQL Oracle. For Support =========== Email: [email protected] Contact Form: http://www.learninhindi.com/home/contact Our Social Media ================ Facebook: https://www.facebook.com/LearnInHindi Twitter: https://twitter.com/LearnInHindi For Training & Videos ===================== For more videos and articles visit: http://www.learninhindi.com Free Java Programming In Hindi Course ===================================== https://www.youtube.com/playlist?list=PLOZ3jentlCDAwwhMyoLISrxkXTADGp7PH Free Oracle PL/SQL Programming In Hindi Course ============================================== https://www.youtube.com/playlist?list=PLB5DA82419C2D99B6 Free C Programming In Hindi Course ================================== https://www.youtube.com/playlist?list=PLOZ3jentlCDAxKpBLMWogxSdy6BZcsAJq Trips & Tricks Channel ====================== https://www.youtube.com/channel/UCGmLfkuCo-3lHHJXRJ9HUMw Programming in Hindi Channel ============================ https://www.youtube.com/channel/UCudElIDgwNrybeAvXIy1HZQ
Views: 3630 ITORIAN
Pebbles present, Learn Oracle 10g with Step By Step Video Tutorials. Learn Oracle 10g Tutorial series contains the following videos : Learn Oracle - History of Oracle Learn Oracle - What is Oracle - Why do we need Oracle Learn Oracle - What is a Database Learn Oracle - What is Grid Computing Learn Oracle - What is Normalization Learn Oracle - What is ORDBMS Learn Oracle - What is RDBMS Learn Oracle - Alias Names, Concatenation, Distinct Keyword Learn Oracle - Controlling and Managing User Access (Data Control Language) Learn Oracle - Introduction to SQL Learn Oracle - Oracle 10g New Data Types Learn Oracle - How to Alter a Table using SQL Learn Oracle - How to Create a Package in PL SQL Learn Oracle - How to Create a Report in SQL Plus Learn Oracle - How to Create a Table using SQL - Not Null, Unique Key, Primary Key Learn Oracle - How to Create a Table using SQL Learn Oracle - How to Create a Trigger in PL SQL Learn Oracle - How to Delete Data from a Table using SQL Learn Oracle - How to Drop and Truncate a Table using SQL Learn Oracle - How to Insert Data in a Table using SQL Learn Oracle - How to open ISQL Plus for the first time Learn Oracle - How to Open SQL Plus for the First Time Learn Oracle - How to Update a Table using SQL Learn Oracle - How to use Aggregate Functions in SQL Learn Oracle - How to use Functions in PL SQL Learn Oracle - How to use Group By, Having Clause in SQL Learn Oracle - How to Use Joins, Cross Join, Cartesian Product in SQL Learn Oracle - How to use Outer Joins (Left, Right, Full) in SQL Learn Oracle - How to use the Character Functions, Date Functions in SQL Learn Oracle - How to use the Merge Statement in SQL Learn Oracle - How to use the ORDER BY Clause with the Select Statement Learn Oracle - How to use the SELECT Statement Learn Oracle - How to use the Transactional Control Statements in SQL Learn Oracle - How to use PL SQL Learn Oracle - Data Types in PL SQL Learn Oracle - Exception Handling in PL SQL Learn Oracle - PL SQL Conditional Logics Learn Oracle - PL SQL Cursor Types - Explicit Cursor, Implicit Cursor Learn Oracle - PL SQL Loops Learn Oracle - Procedure Creation in PL SQL Learn Oracle - Select Statement with WHERE Cause Learn Oracle - SQL Operators and their Precedence Learn Oracle - Using Case Function, Decode Function in SQL Learn Oracle - Using Logical Operators in the WHERE Clause of the Select Statement Learn Oracle - Using Rollup Function, Cube Function Learn Oracle - Using Set Operators in SQL Learn Oracle - What are the Different SQL Data Types Learn Oracle - What are the different types of Databases Visit Pebbles Official Website - http://www.pebbles.in Subscribe to our Channel – https://www.youtube.com/channel/UCNNjWVsQqaMYccY044vtHJw?sub_confirmation=1 Engage with us on Facebook at https://www.facebook.com/PebblesChennai Please Like, Share, Comment & Subscribe
Views: 182 Pebbles Tutorials
In Telugu: SQL UNIQUE Constraint Telugu In Telugu: Unique Key Constraint in SQL Server SQL UNIQUE Constraint SQL Server: Unique Constraints Oracle / PLSQL: Unique Constraints Create Unique Constraints Creating a UNIQUE constraint The UNIQUE constraint ensures that all values in a column are different. Both the UNIQUE and PRIMARY KEY constraints provide a guarantee for uniqueness for a column or set of columns. SQL Server: Unique Constraints Oracle / PLSQL: Unique Constraints Create Unique Constraints How can I create a unique constraint on my column In English: download sql study material Website: http://www.vlrtrain.in/2016/09/download-sql-files.html Learn SQL sql tutorial for beginners sql commands oracle sql tutorial sql tutorial advanced mysql tutorial sql tutorial video SQL Tutorial, Tutorials SQL
Views: 835 VLR Training
what is mean by primary key?? ans: It has unique value in each row of data.it cannot contain null values what is foreign key?? ans: It is defined in second table,but it refers to the primary key in the first table
Views: 140 SB TUTORIALS
How to use Unique Key Constraint in Oracle or what is Constraints and Types of Constraints in an Oracle SQL Database | integrity Constraints in SQL Unique Key Constraint is nothing but its allowing Unique and Null Values in Columns Explaining constraints and types of constraints in oracle or Constraints in Oracle SQL database or Constraints is nothing but a set of rules which is applied to the columns of any table in the database Assignment: Assignment link will be available soon: In this series we cover the following topics: SQL basics, create table oracle, SQL functions, SQL queries, SQL server, SQL developer installation, Oracle database installation, SQL Statement, OCA, Data Types, Types of data types, SQL Logical Operator, SQL Function,Join- Inner Join, Outer join, right outer join, left outer join, full outer join, self-join, cross join, View, SubQuery, Set Operator. follow me on: Facebook Page: https://www.facebook.com/LrnWthr-319371861902642/?ref=bookmarks Contacts Email: [email protected] Instagram: https://www.instagram.com/equalconnect/ Twitter: https://twitter.com/LrnWthR
Views: 13 EqualConnect Coach
الدرس الخامس من سلسلة دروس تعلم أوراكل محتويات الدرس: 1- NULL Values. 2- Null values in Arithmetic Expressions. 3- Column Alias. ........................................................... تواصل معانا علي الفيس بوك من هنا : https://www.facebook.com/askgad ........................................................... تواصل معانا علي موقعنا من هنا : https://www.askgad.com/
Views: 3412 Ask Gad
SQL is a standard Structured query language for storing, manipulating and retrieving data in databases. NOT NULL , UNIQUE , PRIMARY KEY , FOREIGN KEY , CHECK , INDEX , default 1) NOT NULL - Ensures that a column cannot have a NULL value 2) UNIQUE - Ensures that all values in a column are different 3) PRIMARY KEY - A combination of a NOT NULL and UNIQUE. Uniquely identifies each row in a table 4) FOREIGN KEY - Uniquely identifies a row/record in another table. The table containing the foreign key is called the child table, and the table containing the candidate key is called the referenced or parent table. prevents invalid data and destroy links between tables. 5) CHECK - Ensures that all values in a column satisfies a specific condition 6) DEFAULT - Sets a default value for a column when no value is specified 7) INDEX - Used to create and retrieve data from the database very quickly.
Views: 10 R K
In this video discusses Null, Unique and Primary Key constraints of SQL. It also covers demonstration of these constraints in Oracle.
Primary key in Oracle what is primary key ? 1) Primary key is a single field or combination of fields that uniquely identified. 2)The primary key can not contain a null value. 3)A table can have only one primary key. 4)Primary keys must contain UNIQUE values. 5)Table can have only ONE primary key. CREATE TABLE Employee ( emp_id numeric(10) not null, name varchar2(50) not null, city varchar2(50), CONSTRAINT id_pk PRIMARY KEY (emp_id) ); Other option to Add ALTER TABLE Employee ADD CONSTRAINT id_pk PRIMARY KEY (emp_id); The syntax to drop a primary key : ALTER TABLE Employee DROP CONSTRAINT id_pk; #techquerypond https://techquerypond.wordpress.com https://techquerypond.com https://twitter.com/techquerypond
Views: 176 Tech Query Pond
DISTINCT Clause in Oracle
Views: 4189 Naresh i Technologies
This video is the 1st video in the series of 'working with null in oracle sql', the video demonstrates the purpose and use of NVL function in oracle with perfect and easy to understand example. The NVL function is used to replace NULL values by another value.
Views: 1380 Kishan Mashru
In this video we will learn about the different ways to replace NULL values in sql server. 1. ISNULL() function 2. CASE statement 3. COALESCE() function Text version of the video http://csharp-video-tutorials.blogspot.com/2012/08/different-ways-to-replace-null-in-sql.html Slides http://csharp-video-tutorials.blogspot.com/2013/08/part-15-different-ways-to-replace-null.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists
Views: 258939 kudvenkat
Course : Oracle SQL Online Training Mode of Training : Online Duration : 40 Hours Timings : Flexible Oracle SQL Online Training Demo Registration Link : http://svsoftsolutions.com/demo.aspx Introduction to SQL What is SQL? What Can SQL do? RDBMS SQL Syntax Database Tables SQL Statements Overview of Most Important SQL Commands SELECT UPDATE DELETE INSERT CREATE TABLE ALTER TABLE DROP TABLE CREATE INDEX DROP INDEX SQL SELECT Statement SELECT syntax Demo Database SELECT Column Example SELECT * Example SQL Distinct SELECT DISTINCT Statement SELECT DISTINCT Syntax SELECT DISTINCT Example SQL WHERE Clause WHERE Clause WHERE Clause Example Operators in the WHERE Clause SQL AND & OR Operators AND Operator Example OR Operator Example Combining AND & OR SQL ORDER BY ORDER BY Syntax ORDER BY Example ORDER BY DESC Example ORDER BY Several Column Examples SQL Insert Into INSERT INTO Syntax INSERT INTO Examples Insert Data into Specified Columns SQL UPDATE UPDATE Syntax UPDATE Example Watch out UPDATE statement. SQL DELETE DELETE Syntax DELETE Examples Delete All the Data SQL Aliases SQL Alias Syntax for Columns Alias Example for Table Columns Alias Example for Tables. SQL Joins Different SQL JOINs INNER JOIN LEFT OUTER JOIN RIGHT OUTER JOIN FULL OUTER JOIN SQL UNION UNION Syntax UNION Example UNION ALL Syntax UNION ALL Example SQL Insert Into Select INSERT INTO SELECT Syntax INSERT INTO SELECT Examples SQL Create Table CREATE TABLE Syntax CREATE TABLE Example SQL Constraints CREATE TABLE + CONSTRAINT Syntax NOT NULL Constraint UNIQUE Constraint UNIQUE Constraint on CREATE TABLE UNIQUE Constraint on ALTER TABLE To DROP a UNIQUE Constraint PRIMARY KEY Constraint PRIMARY KEY Constraint on CREATE TABLE PRIMARY KEY Constraint on ALTER TABLE To DROP a PRIMARY KEY Constraint FOREIGN KEY Constraint FOREIGN KEY Constraint on CREATE TABLE FOREIGN KEY Constraint on ALTER TABLE To DROP a FOREIGN KEY Constraint CHECK Constraint CHECK Constraint on CREATE TABLE CHECK Constraint on ALTER TABLE To DROP a CHECK Constraint DEFAULT Constraint on CREATE TABLE DEFAULT Constraint on ALTER TABLE To DROP a DEFAULT Constraint SQL Create Index CREATE INDEX Syntax CREATE UNIQUE INDEX Syntax CREATE INDEX Example SQL DROP Command The DROP INDEX Statement The DROP TABLE Statement The DROP DATABASE Statement The TRUNCATE TABLE Statement SQL ALTER Command The ALTER TABLE Statement ALTER TABLE Example Change Data Type Example DROP COLUMN Example SQL VIEWS CREATE VIEW Statement CREATE VIEW Syntax CREATE VIEW Examples CREATE OR REPLACE VIEW Syntax Dropping a View SQL NULL Values Working with NULL Values IS NULL IS NOT NULL SQL NULL Functions NVL COALESCE For more details visit our website : www.svsoftsolutions.com Or reach us @ USA : +1-845-915-8712 (Toll Free), India : +91-9642373173
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In this tutorial, you'll learn the difference between NVL,NVL2 &Coalesce functions PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7). Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. PL/SQL works analogously to the embedded procedural languages associated with other relational databases. For example, Sybase ASE and Microsoft SQL Server have Transact-SQL, PostgreSQL has PL/pgSQL (which emulates PL/SQL to an extent), and IBM DB2 includes SQL Procedural Language, which conforms to the ISO SQL’s SQL/PSM standard. The designers of PL/SQL modeled its syntax on that of Ada. Both Ada and PL/SQL have Pascal as a common ancestor, and so PL/SQL also resembles Pascal in several aspects. However, the structure of a PL/SQL package does not resemble the basic Object Pascal program structure as implemented by a Borland Delphi or Free Pascal unit. Programmers can define public and private global data-types, constants and static variables in a PL/SQL package. PL/SQL also allows for the definition of classes and instantiating these as objects in PL/SQL code. This resembles usage in object-oriented programming languages like Object Pascal, C++ and Java. PL/SQL refers to a class as an "Abstract Data Type" (ADT) or "User Defined Type" (UDT), and defines it as an Oracle SQL data-type as opposed to a PL/SQL user-defined type, allowing its use in both the Oracle SQL Engine and the Oracle PL/SQL engine. The constructor and methods of an Abstract Data Type are written in PL/SQL. The resulting Abstract Data Type can operate as an object class in PL/SQL. Such objects can also persist as column values in Oracle database tables. PL/SQL is fundamentally distinct from Transact-SQL, despite superficial similarities. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages, but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and locking. There are software tools available that claim to facilitate porting including Oracle Translation Scratch Editor, CEITON MSSQL/Oracle Compiler  and SwisSQL. The StepSqlite product is a PL/SQL compiler for the popular small database SQLite. PL/SQL Program Unit A PL/SQL program unit is one of the following: PL/SQL anonymous block, procedure, function, package specification, package body, trigger, type specification, type body, library. Program units are the PL/SQL source code that is compiled, developed and ultimately executed on the database. The basic unit of a PL/SQL source program is the block, which groups together related declarations and statements. A PL/SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. If a variable is not initialized then it defaults to NULL value. The optional exception-handling part is used to handle run time errors. Only the executable part is required. A block can have a label. Package Packages are groups of conceptually linked functions, procedures, variables, PL/SQL table and record TYPE statements, constants, cursors etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body. The specification is the interface to the application; it declares the types, variables, constants, exceptions, cursors, and subprograms available. The body fully defines cursors and subprograms, and so implements the specification. Two advantages of packages are: Modular approach, encapsulation/hiding of business logic, security, performance improvement, re-usability. They support object-oriented programming features like function overloading and encapsulation. Using package variables one can declare session level (scoped) variables, since variables declared in the package specification have a session scope.
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This SQL tutorial discusses the common constraints one can place on a table: NOT NULL, DEFAULT, UNIQUE, and CHECK, including the purpose of each constraint, as well as how to apply each constraint to a table during table creation. 0:24 NOT NULL Constraint 0:56 DEFAULT Constraint 2:03 UNIQUE Constraint 2:34 CHECK Constraint
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