SQLPrepare prepares an SQL string for execution.

When SQLPrepare returns SQL_ERROR or SQL_SUCCESS_WITH_INFO, an associated SQLSTATE value may be obtained by calling SQLError. The following table lists the SQLSTATE values commonly returned by SQLPrepare and explains each one in the context of this function; the notation "(DM)" precedes the descriptions of SQLSTATEs returned by the Driver Manager. The return code associated with each SQLSTATE value is SQL_ERROR, unless noted otherwise.

The application calls SQLPrepare to send an SQL statement to the data source for preparation. The application can include one or more parameter markers in the SQL statement. To include a parameter marker, the application embeds a question mark (?) into the SQL string at the appropriate position.

The driver modifies the statement to use the form of SQL used by the data source, then submits it to the data source for preparation. In particular, the driver modifies the escape clauses used to define ODBC-specific SQL. (For a description of SQL statement grammar, see "Supporting ODBC Extensions to SQL" in Chapter 14, "Processing an SQL Statement," and Appendix C, "SQL Grammar.") For the driver, an hstmt is similar to a statement identifier in embedded SQL code. If the data source supports statement identifiers, the driver can send a statement identifier and parameter values to the data source.

Once a statement is prepared, the application uses hstmt to refer to the statement in later function calls. The prepared statement associated with the hstmt may be reexecuted by calling SQLExecute until the application frees the hstmt with a call to SQLFreeStmt with the SQL_DROP option or until the hstmt is used in a call to SQLPrepare, SQLExecDirect, or one of the catalog functions (SQLColumns, SQLTables, and so on). Once the application prepares a statement, it can request information about the format of the format of the result set.

Some drivers cannot return syntax errors or access violations when the application calls SQLPrepare. A driver may handle syntax errors and access violations, only syntax errors, or neither synttax errors nor access violations. Therefore, an application must be able to handle these conditions whenc alling subsequent related functions such as SQLNumResults, SQLDescribeCol, SQLColAttribute and SQLExecute.

Depending on the capabilities of the driver and data source and on whether the application has called SQLBindParameter, parameter information (such as data types) might be checked when the statement is prepared or when it is executed. For maximum interoperability, an application should unbind all parameters that applied to an old SQL statement before preparing a new SQL statement on the same hstmt. This prevents errors that are due to old parameter information being applied to the new statement.

See SQLBindParameter, SQLParamOptions, SQLPutData and SQLSetPos.

ODBC Router

ODBC Router transparently makes all ODBC drivers on a central Windows Server useable by your network's iPhone/iPod, iPad, Linux, Mac and Windows systems. Years in the making here in the USA, ODBC Router has saved its customers millions of dollars in DLL installations and support costs for less than the price of a new PC and a few minutes installation time. ODBC Router provides a low cost, turnkey database network with enterprise class IT support.

Ditching the ODBC Administrator Control Panel:

By linking your application with the free ODBC Router client-side SDK instead of the ODBC Driver Manager, the need for your end-users to deal with driver installation or an ODBC Control Panel is gone! We even provide a setup function your code may call to display a "network browser" that enables your customer to "find" their ODBC Router server on the network, then "choose" the exact database they want to work with and finally return to your application with a fully-formed ODBC connection-string that may be stored and passed back to SQLConnect or SQLDriverConnect anytime your user wants to initiate a connection that data source. No more walking your customers through the process of adding data sources to ODBC Control Panel or, in the case of non-Windows computers, no need to worry about whether or not a compatible third-party ODBC Driver Manager has been installed for use with your code. (Remember that ODBC Router supports iPhone/iPod, iPad, Mac OS 9, Mac OS X, Linux and Windows.) If there ever are any client-side ODBC support issues, AugSoft can handle them directly with the customer freeing you to focus on the application.

JDBC?

JDBC-in-ODBC drivers (like some 'actual' ODBC drivers, lol) launch a CPU-intensive virtual machine in the background on your machine, which is bad for battery powered laptops, high-volume web servers or entry level desktops (that typically have slow busses and drives). As the world shifted to laptops and shared servers, the whole "virtual machine" concept became a support nightmare and so these days good Java apps are compiled to run as native (not emulated) code. Java developers may use the operating system's native ODBC support from within the JDBC class library using the sun.jdbc.odbc.JdbcOdbcDriver driver with a URL as shown below.

jdbc:odbc:dsn[;key=value]*

Example:

jdbc:odbc:finance;UID=cfo;

IT techs may then complete the database connection on the Customer's machine using ODBC Router or the database vendor's official ODBC driver.

NOTE: By creating ODBC data sources with ODBC Router, your apps will enjoy native speed and database independent connections from either Java/C/C++/C#/ObjC or PHP/PERL/Python/Ruby/BASIC on Linux, Macintosh and Windows. Also be aware that using ODBC Router with the Mac platform is an especially good idea because database vendors have not kept their Mac drivers in sync with Windows and there are actual third-party vendors who wrap freeware and JDBC drivers inside of ODBC "shells" without warning their customers! This problem is of great concern to developers because fake drivers almost always fly past the IT guys who test with speed deamon desktops, but fail the enterprise when user laptops and iMacs take too long to run queries or slowly corrupt the database when they do. IT guys often chalk this up to "network problems" leaving users with poison drivers to avoid their database. ODBC Router addresses this issue by enabling official vendor supported Windows ODBC drivers (on a Windows Server) to be accessed from all platforms, network wide.

ODBC 3.x?

It's not here yet. Even in 2010, most ODBC drivers are ODBC 1.x and 2.x. The ODBC Driver Manager translates between 3.x and 2.x or 2.x and 1.x ODBC calls. Therefore, if you don't need UNICODE, it's a bad idea to use ODBC 3.x API calls. That said, UNICODE is a Good Thing and there are actually at least three databases that natively support it now, so look for 3.x to be here soon.

Need ODBC API Help?

We really know ODBC and we routinely provide code-level ODBC help to our customers. Our low cost ODBC Router systems are available now at our online store and if your site buys them, you may open a ticket to ask ODBC development questions --we offer both E-Mail and On-Call support options in seven of the G8's timezones! Be sure to test your ODBC Router and ask for any needed installation help before purchase because we aren't Fry's --no refunds please, our prices are too low for such nonsense and we're too busy supporting real Customers!