Core functionality

The Core interface conformance level provides all the basic functionality  an application needs in order to work with a data source. The standard ODBC API subset defined for Core level conformance provides all of the functionality defined in the ISO CLI specification and all of the non-optional functionality defined in the 1992 X/Open CLI specification. A Core-level interface – conformant ODBC driver allows the application to do all of the following:

• Allocate and free all types of handles by calling SQLAllocHandle and SQLFreeHandle.
• Bind result data set columns to application variables by calling SQLBindCol.
• Handle dynamic parameters, including arrays of parameters (but only in the input direction), by calling SQLBindParameter and SQLNumParams.
• Specify a bind offset.
• Use the data-at-execution dialog, involving calls to SQLParamData and SQLPutData.
• Manage cursors and cursor names, by calling SQLCloseCursor, SQLGetCursorName, and SQLSetCursorName.
• Gain access to the description (metadata) of result data sets, by calling SQLColAttribute, SQLDescribeCol, SQLNumResultCols, and SQLRowCount.
• Query the data dictionary by calling the catalog functions SQLColumns, SQLGetTypeInfo, SQLStatistics, and SQLTables.
• Manage data sources and connections by calling SQLConnect, SQLDataSources, SQLDisconnect, and SQLDriverConnect.
• Obtain information about drivers, no matter which ODBC level they support, by calling SQLDrivers.
• Prepare and execute SQL statements using the dynamic SQL model of the SQL-92 standard (i.e. prepare and execute a statement, optionally supplying parameter values at runtime), by calling SQLExecDirect, SQLExecute, and SQLPrepare.
• Fetch a single row or multiple rows of data from a result data set (in the forward direction only) by calling SQLFetch, or by calling SQLFetchScroll with the FetchOrientation argument set to SQL_FETCH_NEXT.
• Retrieve data in parts from an unbound column of a result data set by calling SQLGetData.
• Obtain the current values of all environment, connection, and SQL statement attributes by calling SQLGetConnectAttr, SQLGetEnvAttr, and SQLGetStmtAttr, set all attributes to their default values, and set certain attributes to non-default values by calling SQLSetConnectAttr, SQLSetEnvAttr, and SQLSetStmtAttr.
• Manipulate certain fields of descriptors by calling SQLCopyDesc, SQLGetDescField, SQLGetDescRec, SQLSetDescField, and SQLSetDescRec.
• Obtain diagnostic information about a field of a record by calling SQLGetDiagField and SQLGetDiagRec.
• Detect driver capabilities by calling SQLGetFunctions and SQLGetInfo.
• Detect the result of any text substitutions made to an SQL statement before it is sent to the data source by calling SQLNativeSql
• Commit a transaction using the syntax of SQLEndTran.
• Call SQLCancel to cancel the data-at-execution dialog and, in multithread environments, cancel an ODBC function executing in another thread. Core level interface conformance does not mandate support for asynchronous execution of functions, nor for the ability to cancel an ODBC function that is executing asynchronously. Neither the platform, nor the ODBC driver need be multithread for the driver to conduct independent activities at the same time. However, in multithread environments, the ODBC driver must be thread-safe. Serialization of requests from the application is a conformant way to implement this specification, even though it may create serious performance problems.
• Obtain row-identifying column information for any table in the data source by calling SQLSpecialColumns