alter data sql code example

Example 1: sql update query

--update query example
 UPDATE table_name
 SET column1 = value1, column2 = value2, ...
 WHERE condition;

Example 2: sql update from select

UPDATE YourTable 
SET Col1 = OtherTable.Col1, 
    Col2 = OtherTable.Col2 
FROM (
    SELECT ID, Col1, Col2 
    FROM other_table) AS OtherTable
WHERE 
    OtherTable.ID = YourTable.ID

Example 3: sql update from select

UPDATE
    Table_A
SET
    Table_A.col1 = Table_B.col1,
    Table_A.col2 = Table_B.col2
FROM
    Some_Table AS Table_A
    INNER JOIN Other_Table AS Table_B
        ON Table_A.id = Table_B.id
WHERE
    Table_A.col3 = 'cool'

Example 4: sql alter table

Adds, deletes or edits columns in a table. It can also be used to add and
delete constraints in a table, as per the above.
Example: Adds a new boolean column called ‘approved’ to a table named
‘deals’.
ALTER TABLE deals
ADD approved boolean;
Example 2: Deletes the ‘approved’ column from the ‘deals’ table
ALTER TABLE deals
DROP COLUMN approved;

Example 5: sql alter table

-- With check if field already exists

IF NOT EXISTS(SELECT 1 FROM sys.columns 
          WHERE Name = N'Email'
          AND Object_ID = Object_ID(N'dbo.Customers'))
BEGIN    
	ALTER TABLE Customers
    ADD Email varchar(255);
END

Tags:

Php Example

Recent Posts