importliquibase.statement.core.DropForeignKeyConstraintStatement;//导入依赖的package包/类publicSql[] generateSql(DropForeignKeyConstraintStatementstatement, Database database, SqlGeneratorChain sqlGeneratorChain) {if(databaseinstanceofMySQLDatabase || databaseinstanceofMaxDBDatabase || databaseinstanceofSybaseAS...
Because theauthorstable has a dependent object which is a foreign key that references thepagestable, PostgreSQL issues an error message: ERROR: cannotdroptableauthorsbecause other objects dependonitDETAIL:constraintpages_author_id_fkeyontablepages dependsontableauthorsHINT:UseDROP... CASCADEtodropthedepe...
# 需要导入模块: from migrate.changeset.constraint import ForeignKeyConstraint [as 别名]# 或者: from migrate.changeset.constraint.ForeignKeyConstraint importdrop[as 别名]defdrop_constraints_and_alter_types(primary_table_name, foreign_tables, revision_table_name):# 1dropall foreign key constraintsdropped_...
postgres=# ALTER TABLE recordpostgres-# DROP CONSTRAINT record_pkey;ALTER TABLE Now, let’s see the table description. We shouldn’t see the line. "record_pkey" PRIMARY KEY, btree (id) TheIDcolumn will still be in the table because we’re removing the primary key constraint, not the ent...
so we created a foreign key from our table to the_timescaledb_catalog.chunktable. But when timescale drops chunks either on policy-driven schedule or manually viapublic.drop_chunks/_timescaledb_functions.drop_chunk, the foreign key constraint is not respected: chunk ids that are no longer va...
Points to remember before dropping the foreign key: The name of the foreign key is needed beforehand. A key is required to drop the constraint from the table. The drop command without knowing the key name leads to the error shown below: The SHOW CREATE TABLE command is compulsory.Author...
Always use a transaction when using complex DDL like DROP with CASCADE, and verify whether any problematic tables that are referenced e.g. via a foreign key constraint were not affected negatively by the command, before running COMMIT.
The output indicates that the statement removes both thecategory_idcolumn and theforeign key constraintthat involves thecategory_idcolumn. 2) Drop a column that is referenced by a constraint First, attempt to remove thepublisher_idcolumn from thebookstable: ...
1.多对一因为是关联关系,所以我们必须指定两个类来进行相互操作,这里涉及到一个外键的操作,即ForeignKey字段,而且外键要定义在多的一方。...limit_choices_to=None, # 在Admin或ModelForm中显示关联数据时,提供的条件,字典类型 db_constraint=True # 是否在数据库中创建外键约束...parent_link=False #...
CONSTRAINT \`FK_6b220c64c020af86108d77d4d0a\` FOREIGN KEY (\`autotaskCompanies\`) REFERENCES \`at_companies\`(\`id\`) ON DELETE NO ACTION ON UPDATE NO ACTION`);}publicasyncdown(queryRunner:QueryRunner):Promise<void>{awaitqueryRunner.query(`ALTER TABLE \`at_tickets\` DROP FOREIGN KEY ...