mysql on delete cascade

First, create two tables STU,SCCreate TableStu (SidintUNSIGNEDPrimary KeyAuto_increment,namevarchar( -) not NULL) TYPE=InnoDB CharSet=UTF8;Create TableSC (SCIDintUNSIGNEDPrimary KeyAuto_increment,sidintUNSIGNED not NULL, scorevarchar( -)default

Parent-Child tables are often involved when adding, modifying, and deleting records in a database.For example, a province table and a city table have a foreign key province_id referenced to the primary key of the province table. In this way, we can

[Mysql] the disadvantage of external key cascade and cascade, mysql key-level disadvantage When creating a table, you can set delete and update to cascade. An example is used to describe the concept of cascade of Foreign keys. Assume that a

MySQL supports foreign key storage engine only InnoDB, when creating foreign keys, requires the parent table must have a corresponding index, the child table when creating foreign keys will also automatically create the corresponding index. When you

MySQL supports foreign key storage engine only InnoDB, when creating foreign keys, requires the parent table must have a corresponding index, the child table when creating foreign keys will also automatically create the corresponding index. When you

Mysql implements cascade operations (cascade update and cascade deletion) and mysql implements 1. Create two tables stu, SC Create table stu (sid int UNSIGNED primary key auto_increment, name varchar (20) not null) TYPE = InnoDB charset = utf8;

We usually have this requirement: delete the records in Table 1, and you need to delete several records related to table 1 in the other tables.For this, we have two workarounds:One, foreign key constraints using the InnoDB tableALTER TABLE ' score

When you are building a table, you can set up cascading for deleting delete and modifying update. The concept of a foreign-key cascade Cascade is illustrated with an exampleIf there is a usertable in the database as follows:This user table is very

The use of foreign keys in MySQL to implement cascade Delete, updateMySQL supports foreign key storage engine only InnoDB, when creating foreign keys, requires the parent table must have a corresponding index, the child table when creating foreign

Mysql cascade operations (instances) and mysql-level operation instances MySQL only supports the InnoDB Storage engine for Foreign keys. When creating foreign keys, the parent table must have corresponding indexes, when a sub-Table creates a