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™ 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. | |