HP NonStop SQL/MP, Руководство по программированию

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Host Variables
HP NonStop SQL/MP Programming Manual for C—429847-008
2-12
Fixed-Point Data Types

To select database values into host variables

To refer to values stored in the database for comparisons
The SETSCALE function has this syntax:
host-variable
is an integer host variable.
indicator-variable
is an indicator variable associated with the host variable.
scale
specifies the scale of
host-variable.
The values for
scale
depend on the size
of
host-variable
:
Follow these guidelines when you use the SETSCALE function:

If you are transferring a value from a host variable to a database using an INSERT
or UPDATE statement, you must assign a value to the host variable that allows for
the scale. For example, to insert a price of $123.45, assign 12345 to hostvar and
specify a scale of 2.

If you are retrieving a value from a database using a SELECT statement, NonStop
SQL/MP returns a value that allows for the scale in the host variable
.
For
example, if your program specifies a scale of 2 in the SELECT statement and
123.45 is stored in the database, SQL/MP returns 12345 to the host variable.

The scale is valid only for SQL statements. If you use the SETSCALE function in
SQL statements and the host variables in calculations using C statements, the
C statements must handle the scale.

To use SETSCALE in an expression, apply the SETSCALE function to each
operand individually rather than to the result of the expression. For example, this
expression adds two prices with a scale of 2 decimal places:
SETSCALE (:price1, 2) + SETSCALE (:price2, 2)
SETSCALE (: host-variable
[ [ INDICATOR ] : indicator-variable ] , scale )
Size Values
2-byte integers 0 – 5 decimal digits
4-byte integers 0 – 10 decimal digits
8-byte integers 0 – 18 decimal digits