Mapping Character Data Types

Embedded SQL for C and SQL Server

Embedded SQL for C and SQL Server

Mapping Character Data Types

You can declare character data types as host variables with a fixed maximum length by explicitly supplying the length of the character array, or by declaring the host variable with an initial value, for example:

EXEC SQL BEGIN DECLARE SECTION;
char var1[18];
char var2[] = "Initialized string";
EXEC SQL END DECLARE SECTION;

In the example, two host variables are declared, each with a maximum length of 18 bytes.

Host variables declared as single-byte characters with no explicit length or initial values (for example, char var[3]) are treated as 1-byte integer data types.

Here is how C character data types are mapped to or from the Microsoft® SQL Server™ 2000 char, varchar, or text data types.

Mapped data types When converted
From C character to SQL Server char, varchar, or text Data is copied and truncated or padded with blanks if the SQL Server table receiving the columns is set to a fixed length.
To C character from SQL Server char, varchar, or text Data is copied and, if necessary, truncated to the length of the receiving field and is terminated with a NULL. If data is truncated, the SQLWARN1 field of the SQLCA data structure is set.