How to Start or Enable and Stop or Disable Extende.What are Extended Events in SQL Server - SQL Serve.How to Delete huge data from a SQL Server Table.Detailed Overview of Model Database in SQL Server.
How to Change Database Name inside Stored Procedur.How to Determine if value is Numeric by using ISNu.How to Concatenate String and Integer Values in SQ.How to Import Image File from File System to SQL S.How to Read Uncommitted Rows from SQL Server Table.How to Add a Column with Values to Existing SQL Se.How to Find Object ( Table.View,Stored Procedure,F.How to Configure Maximum Number of Concurrent Conn.How to Create a SQL Server Agent Job that Calls An.How to Run SQL Server Agent jobs in Batch File - S.Start SQL Server Profiler Trace Automatically Afte.How to Temporarily Disable Maintenance Plan in SQL.How to Avoid Using C drive for Database Create in.How to Enable or Disable SQL Server Agent Job and.How to Find out SQL Server Configuration Changes i.How to Save Query Results to Text or Excel File Fr.Select 'Aamir Shahzad', 'Test Street Address', 'Charlotte', 'NC' Union Select 'M Raza', 'Test Street Address', 'Charlotte', 'NC'Īdd the new column Without Providing NOT NULL Constraint Insert couple of Records in Sample Table Insert into dbo.Customer Create Sample Table without CountryName Column Create table dbo.Customer ( Moving forward if no Country Name provided, It should take USA otherwise value provided. All the existing values should be also updated to default value when we add this new column. What we want to do, we want to add column to existing table with default value. Now company has decided to expand the business and might have the customers from other countries. so we never need Country Column to our existing Table for Address as we only operator in USA. Let's consider we have dbo.Customer table and we are US based company and we never did business outside USA. | 1 | Ramesh | 32 | Ahmedabad | 2000.We often have to add a new column to existing Table/s. Now, the CUSTOMERS table is changed and following would be the output from the SELECT statement. | 7 | Muffy | 24 | Indore | 10000.00 | NULL |įollowing is the example to DROP sex column from the existing table. | ID | NAME | AGE | ADDRESS | SALARY | SEX | Now, the CUSTOMERS table is changed and following would be output from the SELECT statement. | 1 | Ramesh | 32 | Ahmedabad | 2000.00 |įollowing is the example to ADD a New Column to an existing table − The basic syntax of an ALTER TABLE command to DROP PRIMARY KEY constraint from a table is as follows.Ĭonsider the CUSTOMERS table having the following records −
ALTER TABLE ADD COLUMN SQL SERVER CODE
If you're using MySQL, the code is as follows − The basic syntax of an ALTER TABLE command to DROP CONSTRAINT from a table is as follows. The basic syntax of an ALTER TABLE command to ADD PRIMARY KEY constraint to a table is as follows.ĪDD CONSTRAINT MyPrimaryKey PRIMARY KEY (column1, column2.) The basic syntax of an ALTER TABLE command to ADD CHECK CONSTRAINT to a table is as follows.ĪDD CONSTRAINT MyUniqueConstraint CHECK (CONDITION) The basic syntax of ALTER TABLE to ADD UNIQUE CONSTRAINT to a table is as follows.ĪDD CONSTRAINT MyUniqueConstraint UNIQUE(column1, column2.) The basic syntax of an ALTER TABLE command to add a NOT NULL constraint to a column in a table is as follows.ĪLTER TABLE table_name MODIFY column_name datatype NOT NULL The basic syntax of an ALTER TABLE command to change the DATA TYPE of a column in a table is as follows.ĪLTER TABLE table_name MODIFY COLUMN column_name datatype The basic syntax of an ALTER TABLE command to DROP COLUMN in an existing table is as follows.ĪLTER TABLE table_name DROP COLUMN column_name The basic syntax of an ALTER TABLE command to add a New Column in an existing table is as follows.ĪLTER TABLE table_name ADD column_name datatype You should also use the ALTER TABLE command to add and drop various constraints on an existing table.
The SQL ALTER TABLE command is used to add, delete or modify columns in an existing table.
0 kommentar(er)
