// Prepare returns a prepared statement, bound to this connection
func (c *connection) Prepare(query string) (driver.Stmt, error) {
// Allocate the statement handle
var stmtHandle odbc.SQLHandle
ret := odbc.SQLAllocHandle(odbc.SQL_HANDLE_STMT, c.handle, &stmtHandle)
if isError(ret) {
return nil, errorConnection(c.handle)
}
// Set the query timeout
ret = odbc.SQLSetStmtAttr(stmtHandle, odbc.SQL_ATTR_QUERY_TIMEOUT, odbc.SQLPOINTER(queryTimeout.Seconds()), odbc.SQL_IS_INTEGER)
if isError(ret) {
return nil, errorStatement(stmtHandle, query)
}
// Get the statement descriptor table
var stmtDescHandle odbc.SQLHandle
ret = odbc.SQLGetStmtAttr(stmtHandle, odbc.SQL_ATTR_APP_PARAM_DESC, uintptr(unsafe.Pointer(&stmtDescHandle)), 0, nil)
if isError(ret) {
return nil, errorConnection(c.handle)
}
// Parse query options
queryOptions, err := parseQueryOptions(query)
if err != nil {
return nil, err
}
// Remove query options from SQL query
query = removeOptions(query)
// Create new statement
stmt := &statement{handle: stmtHandle, stmtDescHandle: stmtDescHandle, sqlStmt: query, conn: c, queryOptions: queryOptions}
// Add to map of statements owned by the connection
c.statements[stmt] = true
//Add a finalizer
runtime.SetFinalizer(stmt, (*statement).Close)
return stmt, nil
}
// Returns a new connection to the database
func (d *lodbcDriver) Open(name string) (driver.Conn, error) {
// Allocate the connection handle
var connHandle odbc.SQLHandle
ret := odbc.SQLAllocHandle(odbc.SQL_HANDLE_DBC, envHandle, &connHandle)
if isError(ret) {
return nil, errorEnvironment(envHandle)
}
// Establish the connection with the database
nameSqlPtr := (*odbc.SQLCHAR)(unsafe.Pointer(syscall.StringToUTF16Ptr(name)))
ret = odbc.SQLDriverConnect(connHandle, 0, nameSqlPtr, odbc.SQLSMALLINT(odbc.SQL_NTS), nil, 0, nil, odbc.SQL_DRIVER_NOPROMPT)
if isError(ret) {
return nil, errorConnection(connHandle)
}
// Create new connection
var conn = &connection{handle: connHandle, isTransactionActive: false, statements: make(map[driver.Stmt]bool, 0)}
//Add a finalizer
runtime.SetFinalizer(conn, (*connection).Close)
return conn, nil
}
// Allocates shared environment
func init() {
// Set environment handle for connection pooling
ret := odbc.SQLSetEnvAttr(envHandle, odbc.SQL_ATTR_CONNECTION_POOLING, odbc.SQL_CP_ONE_PER_DRIVER, 0)
if isError(ret) {
panic(errorEnvironment(envHandle))
}
// Allocate the environment handle
ret = odbc.SQLAllocHandle(odbc.SQL_HANDLE_ENV, 0, &envHandle)
if isError(ret) {
panic(errorEnvironment(envHandle))
}
// Set the environment handle to use ODBC v3
ret = odbc.SQLSetEnvAttr(envHandle, odbc.SQL_ATTR_ODBC_VERSION, odbc.SQL_OV_ODBC3, 0)
if isError(ret) {
panic(errorEnvironment(envHandle))
}
// Register with the SQL package
d := &lodbcDriver{}
sql.Register("lodbc", d)
}