func (cursor *Cursor) prep() (err error) {
var isc_status [20]C.ISC_STATUS
if err = cursor.check(); err != nil {
return
}
if err = cursor.connection.check(); err != nil {
return
}
C.isc_dsql_describe(&isc_status[0], &cursor.stmt, 1, cursor.o_sqlda)
if err = fbErrorCheck(&isc_status); err != nil {
return
}
cols := cursor.o_sqlda.sqld
var offset C.ISC_SHORT = 0
for count := C.ISC_SHORT(0); count < cols; count++ {
ovar := C.sqlda_sqlvar(cursor.o_sqlda, count)
length, alignment := ovar.sqllen, ovar.sqllen
dtp := ovar.sqltype & ^1
if dtp == C.SQL_TEXT {
alignment = 1
} else if dtp == C.SQL_VARYING {
length += C.SHORT_SIZE
alignment = C.SHORT_SIZE
}
offset = fbAlign(offset, alignment)
ovar.sqldata = (*C.ISC_SCHAR)(unsafe.Pointer((uintptr(unsafe.Pointer(cursor.o_buffer)) + uintptr(offset))))
offset += length
offset = fbAlign(offset, C.SHORT_SIZE)
ovar.sqlind = (*C.ISC_SHORT)(unsafe.Pointer(uintptr(unsafe.Pointer(cursor.o_buffer)) + uintptr(offset)))
offset += C.SHORT_SIZE
}
return
}
func fieldsFromSqlda(sqlda *C.XSQLDA, lowercaseNames bool) []*Field {
cols := sqlda.sqld
if cols == 0 {
return nil
}
ary := make([]*Field, cols)
for count := C.ISC_SHORT(0); count < cols; count++ {
var field Field
sqlvar := C.sqlda_sqlvar(sqlda, count)
dtp := sqlvar.sqltype & ^1
if sqlvar.aliasname_length > 0 {
field.Name = C.GoStringN((*C.char)(unsafe.Pointer(&sqlvar.aliasname[0])), C.int(sqlvar.aliasname_length))
} else {
field.Name = C.GoStringN((*C.char)(unsafe.Pointer(&sqlvar.sqlname[0])), C.int(sqlvar.sqlname_length))
}
if lowercaseNames && !hasLowercase(field.Name) {
field.Name = strings.ToLower(field.Name)
}
field.TypeCode = int(sqlvar.sqltype & ^1)
field.SqlType = sqlTypeFromCode(dtp, sqlvar.sqlsubtype)
field.SqlSubtype = int(sqlvar.sqlsubtype)
field.DisplaySize = int(sqlvar.sqllen)
if dtp == C.SQL_VARYING {
field.InternalSize = int(sqlvar.sqllen + C.SHORT_SIZE)
} else {
field.InternalSize = int(sqlvar.sqllen)
}
field.Precision = precisionFromSqlvar(sqlvar)
field.Scale = int(sqlvar.sqlscale)
field.Nullable = (sqlvar.sqltype & 1) != 0
ary[count] = &field
}
return ary
}
func (cursor *Cursor) Fetch(row interface{}) (err error) {
const SQLCODE_NOMORE = 100
var isc_status [20]C.ISC_STATUS
if err = cursor.prep(); err != nil {
return
}
if err = cursor.connection.check(); err != nil {
return
}
if cursor.eof {
err = &Error{Message: "Cursor is past end of data."}
return
}
// fetch one row
if C.isc_dsql_fetch(&isc_status[0], &cursor.stmt, 1, cursor.o_sqlda) == SQLCODE_NOMORE {
cursor.eof = true
err = io.EOF
return
}
if err = fbErrorCheck(&isc_status); err != nil {
return
}
// create result tuple
cols := cursor.o_sqlda.sqld
ary := make([]interface{}, cols)
// set result value for each column
for count := C.ISC_SHORT(0); count < cols; count++ {
var val interface{}
// sqlvar := &cursor.o_sqlda.sqlvar[count]
sqlvar := C.sqlda_sqlvar(cursor.o_sqlda, count)
dtp := sqlvar.sqltype & ^1
// check if column is null
if (sqlvar.sqltype&1 != 0) && (*sqlvar.sqlind < 0) {
val = nil
} else {
// set column value to result tuple
switch dtp {
case C.SQL_TEXT:
val = C.GoStringN((*C.char)(unsafe.Pointer(sqlvar.sqldata)), C.int(sqlvar.sqllen))
case C.SQL_SHORT:
sval := *(*C.short)(unsafe.Pointer(sqlvar.sqldata))
if sqlvar.sqlscale < 0 {
ratio := C.short(1)
for scnt := C.ISC_SHORT(0); scnt > sqlvar.sqlscale; scnt-- {
ratio *= 10
}
dval := sval / ratio
val = dval
} else {
val = int16(sval)
}
}
}
ary[count] = val
}
switch row := row.(type) {
case *[]interface{}:
*row = ary
}
return
}