Mysql on delete set null

Update foreign key value in mysql

SET foreign_key_checks = 0;
UPDATE languages SET id='xyz' WHERE id='abc';
UPDATE categories_languages SET language_id='xyz' WHERE language_id='abc';
SET foreign_key_checks = 1;

Source: stackoverflow.com

How to delete the rows with null values in mysql

DELETE FROM user WHERE username IS NULL;

To Delete the Rows with the Null values if present in any specific Columns.

Mysql on delete set null

    FOREIGN KEY (child_col1, child_col2, ... child_col_n)
    REFERENCES parent_table (parent_col1, parent_col2, ... parent_col_n)
    ON DELETE SET NULL
    [ ON UPDATE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ]

Source: techonthenet.com

Similar codes

0 vote308 views1 answer
Sql query with date
SQL
0 vote347 views1 answer
Postgresql create table many-to-many
SQL
0 vote333 views1 answer
Create dump file mysql workbench
SQL
7 votes322 views3 answers
How to check table name in current database sql
SQL
0 vote389 views1 answer
Site:av.ru "files"
SQL
5 votes344 views1 answer
Mysql last day of next month
SQL
1 vote347 views2 answers
Select into temp table
SQL
0 vote387 views1 answer
Insert into using contant values and source table columns with sql
SQL
1 vote346 views1 answer
Age postgres
SQL
0 vote336 views1 answer
Starting mysql shell lampp ubuntu
SQL