SET FOREIGN_KEY_CHECKS = 0 Īs another alternative, if the scripts don't specify ENGINE= for the tables, you could temporarily change the default storage engine for the session to MyISAM, before executing the script to create the tables. Make sure the changes you make put the database in a consistent state, where there are no rows that violate constraints. With the foreign key checks disabled, MySQL will allow DML changes (INSERT/UPDATE/DELETE) that would otherwise violated the foreign key constraints. The quick fix is to disable foreign key checks for the session, and then re-enable them.
#UPDATE TABLE MYSQL UPDATE#
I tried to update truck first and it won't work either. All the row insertion statements in the given script have full information and there are row with regnum = sst005. This script is given by the lecturer and has no error.Īnd this will give me an error "cannot delete/ update parent row.
CREATE TABLE TRIP(ĬONSTRAINT TRIP_FKEY1 FOREIGN KEY(LNUM) REFERENCES DRIVER(LNUM)ĬONSTRAINT TRIP_FKEY2 FOREGIN KEY(REGNUM) REFERENCES TRUCK(REGNUM) ) Īnd there are some row insertion statements too. When MySQL sees one of these statements it puts the statement in a queue rather than directly into the table if other insert or update statements are coming. Another condition is that you cannot alter or drop constraints.Ĭontents of Create table script: CREATE TABLE TRUCK(ĬONSTRAINT TRUCK_PKEY PRIMARY KEY(REGNUM),ĬONSTRAINT TRUCK_STATUS CHECK (STATUS IN ('AVAILABLE', 'MAINTAINED', 'USED')) Īnd there are some row insertion statements. I am writing a script that has to update some rows without changing the contents of another script that creates a few tables.
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