Displays values from data records in a record stream on the current default output device. PRINT is intended for testing and learning. Using PRINT, you can type a query at the terminal and see the results immediately. You can also use the SET OUTPUT statement to write the results to a file or another output device. PRINT is valid only in RDO. To retrieve values in an RDBPRE program, use the GET statement to assign database values to host language variables. RDO Example: RDO> FOR J IN JOBS cont> PRINT J.JOB_CODE, J.JOB_TITLE cont> END_FOR
1 – More
If you have invoked a database, you have the necessary privileges to use the PRINT statement. You can use the PRINT statement in three ways: o When you establish a record stream with the FOR or START_ STREAM statement, you use the PRINT statement to write values from the current record stream to the output device. In the case of START_STREAM, you also need FETCH to indicate the current record in the stream. o You can also use PRINT alone, without a FOR or FETCH statement, to retrieve the result of a statistical function. The record stream is formed by the record selection expression within the statistical expression. o You can use PRINT...RDB$DB_KEY in a STORE...END_STORE block to display the database key of the record just stored. Example: RDO> STORE E IN EMPLOYEES USING cont> E.EMPLOYEE_ID = "15231"; cont> E.LAST_NAME = "Smith"; cont> PRINT E.RDB$DB_KEY cont> END_STORE RDB$DB_KEY 21:339:0
2 – Format
(B)0[m[4mPRINT[m qqqwqwqqq> value-expr qqqqqqqqwqwqqq> x mqqq> context-var . * qqqj x mqqqqqqqqqqqqqq , <qqqqqqqqqqj Also see STORE syntax for example of using PRINT...RDB$DB_KEY in RDO within a STORE...END_STORE block.
2.1 – value-expr
A valid Oracle Rdb value expression. Request HELP on Value_expr for more information.
2.2 – context-var
A context variable you have defined in a FOR or START_STREAM statement. Use a context variable and a wildcard character (*) to display all the fields for each record in the record stream. If you use the wildcard character, RDO uses the field names as column headers on the display.
3 – Examples
Example 1 Retrieve all the field values from one or more relations RDO> START_TRANSACTION READ_ONLY RDO> RDO> FOR E IN EMPLOYEES cont> PRINT E.* cont> END_FOR RDO> RDO> COMMIT You can use the wildcard character (*) to display all fields from one or more relations named in your RSE. RDO displays the names of the fields as column headers and displays the corresponding field values beneath them. When you use the wildcard character, you cannot display values for segmented strings, literals, or statistical expressions. This RDO query displays all the field values from each record in the EMPLOYEES relation. Example 2 Retrieve values from named fields in a relation: RDO> START_TRANSACTION READ_ONLY RDO> RDO> FOR E IN EMPLOYEES cont> PRINT E.LAST_NAME, E.FIRST_NAME, E.MIDDLE_INITIAL cont> END_FOR RDO> RDO> COMMIT This RDO query displays field values from each record in the EMPLOYEES relation. Example 3 Retrieve values from fields in two relations: RDO> START_TRANSACTION READ_ONLY RDO> RDO> FOR E IN EMPLOYEES CROSS JH IN JOB_HISTORY cont> OVER EMPLOYEE_ID cont> WITH JH.JOB_END MISSING cont> PRINT E.LAST_NAME, JH.JOB_CODE cont> END_FOR RDO> RDO> COMMIT This RDO statement performs a join of two relations and uses PRINT to display a value from each. The result is the last name and current job code of each employee. Example 4 Retrieve the result of a statistical expression: RDO> START_TRANSACTION READ_ONLY RDO> RDO> PRINT COUNT OF E IN EMPLOYEES WITH cont> E.STATE = "MA" RDO> RDO> COMMIT This example retrieves the number of employees who live in Massachusetts.