The SQL commands (UPDATE and DELETE) are used to modify the data that is already in the database. The SQL DELETE command uses a WHERE clause.
SQL UPDATE statement is used to change the data of the records held by tables. Which rows is to be update, it is decided by a condition. To specify condition, we use WHERE clause.
The UPDATE statement can be written in following form:
Let's see the Syntax:
Let's take an example: here we are going to update an entry in the source table.
See the result after updating value:
Updating Multiple Fields:
If you are going to update multiple fields, you should separate each field assignment with a comma.
SQL UPDATE statement for multiple fields:
Result of the table is given below:
MYSQL SYNTAX FOR UPDATING TABLE:
SQL UPDATE SELECT:
SQL UPDATE WITH SELECT QUERY:
We can use SELECT statement to update records through UPDATE statement.
You can also try this one -
My SQL SYNTAX:
If you want to UPDATE with SELECT in My SQL, you can use this syntax:
Let's take an example having two tables. Here,
First table contains -
And the second table contains -
SQL UPDATE COLUMN:
We can update a single or multiple columns in SQL with SQL UPDATE query.
SQL UPDATE EXAMPLE WITH UPDATING SINGLE COLUMN:
This SQL UPDATE example would update the student_id to '001' in the student table where student_name is 'AJEET'.
SQL UPDATE EXAMPLE WITH UPDATING MULTIPLE COLUMNS:
To update more than one column with a single update statement:
This SQL UPDATE statement will change the student name to 'AJEET' and religion to 'HINDU' where the student name is 'RAJU'.