const char *
The TDBC library provides several C procedures that simplify writing a TDBC
driver. They include a procedure that tokenizes a SQL statement, locating
variables to be substituted, and a procedure that accepts a SQL state and
returns an error class for the interpreter error information.
Tdbc_Init must be invoked prior to any other TDBC call. It accepts
a pointer to a Tcl interpreter, and arranges to load the TDBC library. It
returns TCL_OK if the Tcl library was loaded successfully, and
TCL_ERROR otherwise. If TCL_ERROR is returned, the
interpreters result contains the error message.
Tdbc_TokenizeSql accepts a pointer to a Tcl interpreter, and a
pointer to a character string containing one or more SQL
statements. It tokenizes the SQL statements, and returns a pointer to
a Tcl_Obj that contains a list of the tokens that make up the
statement. Concatenating the tokens together will yield the original
SQL code. The returned Tcl_Obj has a reference count of zero. The
caller is responsible for managing the reference count as needed.
See TOKENS below for a description of what may be in the
returned list of tokens.
Tdbc_MapSqlState accepts a pointer to a string, usually five
characters long, that is the SQL state that resulted from a database
error. It returns a character string that is suitable for inclusion as
the error class when constructing the error code for an error in a
TDBC driver. (By convention, the error code is a list having at least
four elements: "TDBC errorClass sqlstate