Function

The SELECT statement obtains data from the database according to the specified conditions.

Note: If your ADABAS file uses super or sub descriptors, Sub/Super Descriptor Handling contains information to minimize search time.

 

Syntax


 

 

ORDER BY CLAUSE:

 

 

UPDATABILITY CLAUSE:

 

query expression	See Query Expression.
order_by_clause	The specification of a user-defined ordering of the resultant table. Otherwise the resultant table is not ordered.
updatability_clause	The explicit indication that this cursor is to be used in conjunction with either an UPDATE and/or DELETE WHERE CURRENT OF CURSOR statement.

  

Description

The SELECT statement is used to obtain data from the database. Please refer to the description of a query expression or query specification (Common Elements) for information on the processing of a SELECT statement.

• When submitted either dynamically the statement must be associated with a PREPARE statement and an associated dynamic cursor. The statement may then select more than one row.

• When used interactively, the statement may again select more than one row. The use of the INTO clause is not permitted.

Limitations

• The use of an ORDER BY clause is only valid within a dynamic or interactive SELECT statement. Its use enables the resultant table to be sorted in a user-defined sequence.

• The use of the FOR UPDATE clause is only valid within a dynamic or interactive SELECT statement.

ANSI Specifics

• The use of a FOR UPDATE clause is not supported.

CONNX Specifics

None.

 

Examples:

Simple Select Example:

SELECT customername, customerid FROM customers WHERE customerid = "ALCAO"

 

Inner Join Example:

SELECT customername, orderid FROM customers c, orders o WHERE c.customerid = o.customerid

 

Outer Join Example:

SELECT customername, orderid FROM customers c, orders o WHERE c.customerid *=o. customerid

 

Sub-query as a Table Example:

SELECT * FROM (SELECT customername, customerid FROM customers WHERE customerid = "ALCAO") a

 

GROUP BY Example:

SELECT customername, sum(o.productquantity * p.productprice) FROM customers c, orders o, products p WHERE c.customerid = o.customerid AND o.productid = p.productid GROUP BY c.customername

 

GROUP BY Ordinal Example:

SELECT customername, sum(o.productquantity * p.productprice) FROM customers c, orders o, products p WHERE c.customerid = o.customerid AND o.productid = p.productid GROUP BY 1

 

ORDER BY Example:

SELECT customername, sum(o.productquantity * p.productprice) FROM customers c, orders o, products p WHERE c.customerid = o.customerid AND o.productid = p.productid ORDER BY c.customername

 

ORDER BY Ordinal Example:

SELECT customername, sum(o.productquantity * p.productprice) FROM customers c, orders o, products p WHERE c.customerid = o.customerid AND o.productid = p.productid ORDER BY 1

 

SELECT Sub-Query:

SELECT * from (SELECT * FROM CONNXDataSync.datasync.TableSynchronizations a, CONNXDataSync.datasync.TableSynchronizations b where a.tableid = b.tableid)  a