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

3 votes113 views1 answer
Ubuntu install postgresql 12
SQL
3 votes151 views3 answers
Your password does not satisfy the current policy requirements
SQL
2 votes145 views1 answer
Sql find missing values between two tables
SQL
0 vote161 views2 answers
Postgresql get long running queries
SQL
1 vote160 views1 answer
Oracle sql first day of year
SQL
13 votes171 views1 answer
Sql join 3 tables on id
SQL
0 vote315 views1 answer
Current month transactions in mysql
SQL
0 vote150 views1 answer
Work around for mutating problem in Oracle Triggers. Please check it out.
SQL
2 votes210 views2 answers
Create table mysql integer NOT null
SQL
0 vote142 views1 answer
Restart sql server command line linux
SQL