SQL Language Reference / Clauses |
Specify the tables from which the other clauses of the query can access columns for use in expressions.
FROM table-expression [ , table-expression ] *
The FROM clause is a mandatory clause in a select-expression. It specifies the tables (table-expression) from which the other clauses of the query can access columns for use in expressions.
SELECT CUST_NAME FROM TRADE.CUSTOMERS WHERE CID < 5 -- other types of TableExpressions SELECT TABLENAME, ISINDEX FROM SYS.SYSTABLES T, SYS.SYSCONGLOMERATES C WHERE T.TABLEID = C.TABLEID ORDER BY TABLENAME, ISINDEX -- force the join order SELECT * FROM TRADE.SECURITIES S, TRADE.PORTFOLIO F WHERE SEC_ID = F.SID AND F.TID = ? -- a TableExpression can be a joinOperation. Therefore -- you can have multiple join operations in a FROM clause SELECT * FROM TRADE.CUSTOMERS C LEFT OUTER JOIN TRADE.PORTFOLIO F LEFT OUTER JOIN TRADE.SELLORDERS SO ON F.CID = SO.CID ON C.CID= F.CID WHERE SO.SID < 100 AND SO.QTY > 500