Purpose

Specifies a foreign key for a constraint.

Syntax

FOREIGN KEY (fcolumn_name) 
   REFERENCES ref_table (pcolumn_name)

where:

fcolumn_name
specifies the foreign key column to which the constraint is applied. The data type of this column must be the same as the data type of the column it references.
ref_table
specifies the table to which the foreign key refers.
pcolumn_name
specifies the primary key column in the referenced table. For Salesforce, the primary key column is always the rowId column.

Example

Assuming the current schema is SFORCE, the remote table emp is created with the name, empId, and deptId columns. The table contains a foreign key constraint on the deptId column, referencing the rowId in the dept table created in Example C. For the operation to succeed, the data type of the deptId column must be the same as that of the rowId column.

CREATE TABLE emp (name TEXT(30), empId NUMBER(9, 0) EXT_ID, deptId TEXT(18), FOREIGN KEY(deptId) REFERENCES dept(rowId))