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19 mar 2019 · I'm trying to find a query which will return me a list of the foreign keys for a table and the tables and columns they reference. I am half way there with. SELECT a.table_name, a.column_name, a.constraint_name, c.owner FROM ALL_CONS_COLUMNS A, ALL_CONSTRAINTS C where A.CONSTRAINT_NAME = C.CONSTRAINT_NAME and a.table_name=:TableName and C.
14 paź 2008 · If you also want to get the name of the foreign key column: SELECT i.TABLE_SCHEMA, i.TABLE_NAME, i.CONSTRAINT_TYPE, i.CONSTRAINT_NAME, k.COLUMN_NAME, k.REFERENCED_TABLE_NAME, k.REFERENCED_COLUMN_NAME FROM information_schema.TABLE_CONSTRAINTS i LEFT JOIN information_schema.KEY_COLUMN_USAGE k ON i.CONSTRAINT_NAME = k.CONSTRAINT_NAME WHERE i.TABLE ...
To allow naming of a FOREIGN KEY constraint, and for defining a FOREIGN KEY constraint on multiple columns, use the following SQL syntax: MySQL / SQL Server / Oracle / MS Access: ALTER TABLE Orders. ADD CONSTRAINT FK_PersonOrder.
To allow naming of a FOREIGN KEY constraint, and for defining a FOREIGN KEY constraint on multiple columns, use the following SQL syntax: MySQL / SQL Server / Oracle / MS Access: ALTER TABLE Orders
To create a new table containing a foreign key column that references another table, use the keyword FOREIGN KEY REFERENCES at the end of the definition of that column. Follow that with the name of the referenced table and the name of the referenced column in parentheses.
23 maj 2017 · LEFT JOIN USER_CONSTRAINTS CONS_R ON CONS_R.CONSTRAINT_NAME = CONS.R_CONSTRAINT_NAME. LEFT JOIN USER_CONS_COLUMNS COLS_R ON COLS_R.CONSTRAINT_NAME = CONS.R_CONSTRAINT_NAME. -- returns only foreign key constraints. WHERE CONS.CONSTRAINT_TYPE = 'R'.
Add a foreign key constraint to a table. If you want to add a foreign key constraint to an existing table, you use the ALTER TABLE statement as follows: ALTER TABLE child_table ADD CONSTRAINT fk_name FOREIGN KEY (col1,col2) REFERENCES parent_table(col1,col2); Code language: SQL (Structured Query Language) (sql) Drop a foreign key constraint
