MP Users

Embedded SQL

HP NonStop SQL/MX Comparison Guide for SQL/MP Users—523735-003

4-3

INVOKE Directive

In NonStop SQL/MP, use the INVOKE directive interactively through SQLCI to create

host variable declarations in an EDIT file. The EDIT file can then be included in an

embedded SQL program.

In NonStop SQL/MX, use the INVOKE directive to create host variable declarations

only directly in an embedded SQL program. Use the INVOKE command in MXCI to

display the table and column names and data types associated with the columns; you

cannot invoke the format of another language (such as COBOL).

For either kind of table, INVOKE does not support the DATEFORMAT clause. INVOKE

returns the ANSI DATETIME data type. The SQL DATEFORMAT function returns a

character string. They are not compatible and cannot be used interchageably.

Data Type Conversion

For information about the valid conversions you can perform with CAST, see the

SQL/MX Reference Manual.

Host Variables With Date-time Data Types

In NonStop SQL/MX, you can convert data to the data type you specify by using the

CAST specification for any expression, whether or not you are using a parameter.

NonStop SQL/MX replaces the SQL/MP TYPE AS clause with the CAST specification.

In previous releases of NonStop SQL/MX, you were required to cast DATE, TIME,

TIMESTAMP, and INTERVAL data types. In NonStop SQL/MX Release 2.0 you can

directly declare them as host variables.

In NonStop SQL/MP, use the CAST function to associate a character or numeric data

type with a dynamic input parameter. Use the TYPE AS clause in the parameter

specification to associate a date-time or interval data type with a parameter.

Indicator Variables

As in NonStop SQL/MP, the primary use of the indicator variable in NonStop SQL/MX

is to indicate whether the value supplied is null. If the source value is null, the value of

the indicator variable is set to less than zero.

However, in NonStop SQL/MX, the indicator variable has another use. If an indicator

variable is associated with a target character host variable in the INTO clause of a

SELECT or FETCH statement, and the length of the target variable is smaller than the

value returned, the truncated string is placed into the host variable, the indicator

variable is set to the length of the source string, and a warning message is issued.

Otherwise, if the length of the target variable is sufficient, the indicator variable is set to