Enable / Disable Foreign Key Constraints in Oracle

oracle_foreign_keys.sql

DECLARE
  /* The name of the schema that should be synchronized. */
  SCHEMA_NAME_ VARCHAR2(4000) := 'YOUR_SCHEMA';

  /* The operation type: */
  /*  ON  — enable foreign keys. */
  /*  OFF — disable foreign keys. */
  OPERATION_   VARCHAR2(4000) := 'OFF';

  PROCEDURE CONSTRAINTS_ON_OFF(TARGET_SCHEMA_ IN VARCHAR2, ACTION_ IN VARCHAR2 := '')
  IS
    SQL_STRING_ VARCHAR2(4000);
    FK_NAME_    VARCHAR2(4000);
    NEW_STATE_  VARCHAR2(4000);
    CURSOR CURSOR_ IS
      SELECT
        'ALTER TABLE ' || OWNER || '.' ||
        TABLE_NAME || ' ' || NEW_STATE_ || ' CONSTRAINT ' || CONSTRAINT_NAME AS sql_string,
        CONSTRAINT_NAME
      FROM
        ALL_CONSTRAINTS
      WHERE
        CONSTRAINT_TYPE = 'R' AND OWNER = TARGET_SCHEMA_
      ORDER BY CONSTRAINT_NAME ASC;
    BEGIN
      IF UPPER(ACTION_) = 'ON'
      THEN
        NEW_STATE_ := 'ENABLE';
      ELSE
        NEW_STATE_ := 'DISABLE';
      END IF;
      OPEN CURSOR_;
      LOOP
        FETCH CURSOR_ INTO SQL_STRING_, FK_NAME_;
        EXIT WHEN CURSOR_%NOTFOUND;
        EXECUTE IMMEDIATE SQL_STRING_;
        DBMS_Output.PUT_LINE('Foreign key ' || FK_NAME_ || ' has been ' || NEW_STATE_ || 'D');
      END LOOP;
      EXCEPTION
      WHEN OTHERS
      THEN
        BEGIN
          DBMS_Output.PUT_LINE(SQLERRM);
        END;
        CLOSE CURSOR_;
    END;
BEGIN
  CONSTRAINTS_ON_OFF(SCHEMA_NAME_, OPERATION_);
END;
/
COMMIT;

Slight alteration of: https://blog.devart.com/how-to-disable-all-foreign-keys-in-oracle-scheme.html