cavegaq.blogg.se

SET NULL, NO ACTION, CASCADE, SET DEFAULT are some of the values of this parameter. ON UPDATE- This is an optional parameter that takes action on the child data after an update on the parent data.ON DELETE- This parameter takes action on child data after the deletion of parent data.The primary key of parent_table is referenced in child_table

Parent_Table- This is the name of parent_table.child_column1, child_column2…child_column_n- It is the name of child_Table columns to reference the primary key in the parent table.F_key- This is a foreign key constraint.column_1, column_2- the columns to be added to the table.Child_Table is the table name which we will create.REFERENCES parent_Table (parent_column1, parent_column2. Hadoop, Data Science, Statistics & othersĬreating a new table with a foreign key requires CREATE TABLE permission in the databaseįOREIGN KEY (child_column1, child_column2.