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.SQL_NTS)
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 ToHandleAndType(handle interface{}) (h api.SQLHANDLE, ht api.SQLSMALLINT) {
switch v := handle.(type) {
case api.SQLHENV:
if v == api.SQLHENV(api.SQL_NULL_HANDLE) {
ht = 0
} else {
ht = api.SQL_HANDLE_ENV
}
h = api.SQLHANDLE(v)
case api.SQLHDBC:
ht = api.SQL_HANDLE_DBC
h = api.SQLHANDLE(v)
case api.SQLHSTMT:
ht = api.SQL_HANDLE_STMT
h = api.SQLHANDLE(v)
default:
panic(fmt.Errorf("unexpected handle type %T", v))
}
return h, ht
}
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.SQL_NTS,
nil, 0, nil, api.SQL_DRIVER_NOPROMPT)
if IsError(ret) {
defer releaseHandle(h)
return nil, NewError("SQLDriverConnect", h)
}
return &Conn{h: h}, nil
}
func (c *Conn) endTx(commit bool) error {
if c.tx == nil {
return errors.New("not in a transaction")
}
c.tx = nil
var howToEnd api.SQLSMALLINT
if commit {
howToEnd = api.SQL_COMMIT
} else {
howToEnd = api.SQL_ROLLBACK
}
ret := api.SQLEndTran(api.SQL_HANDLE_DBC, api.SQLHANDLE(c.h), howToEnd)
if IsError(ret) {
return NewError("SQLEndTran", c.h)
}
err := c.setAutoCommitAttr(api.SQL_AUTOCOMMIT_ON)
if err != nil {
return err
}
return 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.SQLSetEnvUIntPtrAttr(drv.h, api.SQL_ATTR_ODBC_VERSION, api.SQL_OV_ODBC3, 0)
if IsError(ret) {
defer releaseHandle(drv.h)
return NewError("SQLSetEnvUIntPtrAttr", drv.h)
}
//TODO: find a way to make this attribute changeable at runtime
//Enable connection pooling
ret = api.SQLSetEnvUIntPtrAttr(drv.h, api.SQL_ATTR_CONNECTION_POOLING, api.SQL_CP_ONE_PER_HENV, api.SQL_IS_UINTEGER)
if IsError(ret) {
defer releaseHandle(drv.h)
return NewError("SQLSetEnvUIntPtrAttr", drv.h)
}
//Set relaxed connection pool matching
ret = api.SQLSetEnvUIntPtrAttr(drv.h, api.SQL_ATTR_CP_MATCH, api.SQL_CP_RELAXED_MATCH, api.SQL_IS_UINTEGER)
if IsError(ret) {
defer releaseHandle(drv.h)
return NewError("SQLSetEnvUIntPtrAttr", 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
}