func cvtSQLScalar()

in sources/postgres/infoschema.go [552:656]
99 lines of code
43 McCabe index (conditional complexity)

func cvtSQLScalar(conv *internal.Conv, srcCd schema.Column, spCd ddl.ColumnDef, val interface{}) (interface{}, error) {
	switch spCd.T.Name {
	case ddl.Bool:
		switch v := val.(type) {
		case bool:
			return v, nil
		case string:
			return convBool(v)
		}
	case ddl.Bytes:
		switch v := val.(type) {
		case []byte:
			return v, nil
		}
	case ddl.Date:
		// The PostgreSQL driver uses time.Time to represent
		// dates.  Note that the database/sql library doesn't
		// document how dates are represented, so maybe this
		// isn't a driver issue, but a generic database/sql
		// issue.  We explicitly convert from time.Time to
		// civil.Date (used by the Spanner client library).
		switch v := val.(type) {
		case string:
			return convDate(v)
		case time.Time:
			return civil.DateOf(v), nil
		}
	case ddl.Int64:
		switch v := val.(type) {
		case []byte: // Parse as int64.
			return convInt64(string(v))
		case int64:
			return v, nil
		case float32: // Truncate.
			return int64(v), nil
		case float64: // Truncate.
			return int64(v), nil
		case string: // Parse as int64.
			return convInt64(v)
		}
	case ddl.Float32:
		switch v := val.(type) {
		case []byte: // Note: PostgreSQL uses []byte for numeric.
			return convFloat32(string(v))
		case int64:
			return float32(v), nil
		case float32:
			return v, nil
		case float64:
			return float32(v), nil
		case string:
			return convFloat32(v)
		}
	case ddl.Float64:
		switch v := val.(type) {
		case []byte: // Note: PostgreSQL uses []byte for numeric.
			return convFloat64(string(v))
		case int64:
			return float64(v), nil
		case float32:
			return float64(v), nil
		case float64:
			return v, nil
		case string:
			return convFloat64(v)
		}
	case ddl.Numeric:
		switch v := val.(type) {
		case []byte: // Note: PostgreSQL uses []byte for numeric.
			return convNumeric(conv, string(v))
		}
	case ddl.String:
		switch v := val.(type) {
		case bool:
			return strconv.FormatBool(v), nil
		case []byte:
			return string(v), nil
		case int64:
			return strconv.FormatInt(v, 10), nil
		case float32:
			return strconv.FormatFloat(float64(v), 'g', -1, 32), nil
		case float64:
			return strconv.FormatFloat(v, 'g', -1, 64), nil
		case string:
			return v, nil
		case time.Time:
			return v.String(), nil
		}
	case ddl.Timestamp:
		switch v := val.(type) {
		case string:
			return convTimestamp(srcCd.Type.Name, conv.Location, v)
		case time.Time:
			return v, nil
		}
	case ddl.JSON:
		switch v := val.(type) {
		case string:
			return string(v), nil
		case []uint8:
			return string(v), nil
		}
	}
	return nil, fmt.Errorf("can't convert value of type %s to Spanner type %s", reflect.TypeOf(val), reflect.TypeOf(spCd.T))
}