func (c *Conn) PrepareODBCStmt(query string) (*ODBCStmt, error) {
var out api.SQLHANDLE
ret := api.SQLAllocHandle(api.SQL_HANDLE_STMT, api.SQLHANDLE(c.h), &out)
if IsError(ret) {
return nil, NewError("SQLAllocHandle", c.h)
}
h := api.SQLHSTMT(out)
drv.Stats.updateHandleCount(api.SQL_HANDLE_STMT, 1)
b := api.StringToUTF16(query)
ret = api.SQLPrepare(h,
(*api.SQLWCHAR)(unsafe.Pointer(&b[0])), api.SQLINTEGER(len(b)))
if IsError(ret) {
defer releaseHandle(h)
return nil, NewError("SQLPrepare", h)
}
ps, err := ExtractParameters(h)
if err != nil {
defer releaseHandle(h)
return nil, err
}
return &ODBCStmt{
h: h,
Parameters: ps,
usedByStmt: true,
}, nil
}
func (d *Driver) Open(dsn string) (driver.Conn, error) {
var out api.SQLHANDLE
ret := api.SQLAllocHandle(api.SQL_HANDLE_DBC, api.SQLHANDLE(d.h), &out)
if IsError(ret) {
return nil, NewError("SQLAllocHandle", d.h)
}
h := api.SQLHDBC(out)
drv.Stats.updateHandleCount(api.SQL_HANDLE_DBC, 1)
b := api.StringToUTF16(dsn)
ret = api.SQLDriverConnect(h, 0,
(*api.SQLWCHAR)(unsafe.Pointer(&b[0])), api.SQLSMALLINT(len(b)),
nil, 0, nil, api.SQL_DRIVER_NOPROMPT)
if IsError(ret) {
defer releaseHandle(h)
return nil, NewError("SQLDriverConnect", h)
}
return &Conn{h: h}, nil
}
func initDriver() error {
//Allocate environment handle
var out api.SQLHANDLE
in := api.SQLHANDLE(api.SQL_NULL_HANDLE)
ret := api.SQLAllocHandle(api.SQL_HANDLE_ENV, in, &out)
if IsError(ret) {
return NewError("SQLAllocHandle", api.SQLHENV(in))
}
drv.h = api.SQLHENV(out)
drv.Stats.updateHandleCount(api.SQL_HANDLE_ENV, 1)
// will use ODBC v3
ret = api.SQLSetEnvAttr(drv.h, api.SQL_ATTR_ODBC_VERSION,
api.SQLPOINTER(api.SQL_OV_ODBC3), 0)
if IsError(ret) {
defer releaseHandle(drv.h)
return NewError("SQLSetEnvAttr", drv.h)
}
//TODO: find a way to make this attribute changeable at runtime
//Enable connection pooling
ret = api.SQLSetEnvAttr(drv.h, api.SQL_ATTR_CONNECTION_POOLING, api.SQLPOINTER(api.SQL_CP_ONE_PER_HENV), api.SQL_IS_UINTEGER)
if IsError(ret) {
defer releaseHandle(drv.h)
return NewError("SQLSetEnvAttr", drv.h)
}
//Set relaxed connection pool matching
ret = api.SQLSetEnvAttr(drv.h, api.SQL_ATTR_CP_MATCH, api.SQLPOINTER(api.SQL_CP_RELAXED_MATCH), api.SQL_IS_UINTEGER)
if IsError(ret) {
defer releaseHandle(drv.h)
return NewError("SQLSetEnvAttr", drv.h)
}
//TODO: it would be nice if we could call "drv.SetMaxIdleConns(0)" here but from the docs it looks like
//the user must call this function after db.Open
return nil
}