Category: MySQL

UPDATE  `MySQL_Table` SET  `MySQL_Table_Column` = REPLACE(`MySQL_Table_Column`, 'oldString', 'newString') WHERE  `MySQL_Table_Column` LIKE 'oldString%';

When Should I use MySQL Search and Replace?

Doing a Search and Replace via SQL could be dangerous if you have links that you’re unaware of which shouldn’t be changed. You should Search and Replace only when you’re convinced that you have to change the text in your Database. You should always perform a Database backup before proceeding with any manual changes.

To add a foreign key (grade_id) to an existing table (users), follow the following steps:

ALTER TABLE users ADD grade_id SMALLINT UNSIGNED NOT NULL DEFAULT 0;
ALTER TABLE users ADD CONSTRAINT fk_grade_id FOREIGN KEY (grade_id) REFERENCES grades(id);

Source

Prompt for password:

 mysql -u username -p databasename < filename.sql  

Enter password directly (not secure):

 mysql -u username -pPlainPassword databasename filename.sql 

Example:

mysql -u root -p wp_users < wp_users.sql

mysql -u root -pPassword123 wp_users --default-character-set=utf8 < wp_users.sql

See also:
4.5.1.5. Executing SQL Statements from a Text File

Error: 1017 Can’t find file! (errno: 2)

mysql> REPAIR TABLE database.postmeta USE_FRM;