Function BuildUniqueKeyRangeEndPreparedQueryViaOffset

go/sql/builder.go:428–484

(databaseName, tableName string, uniqueKeyColumns *ColumnList, rangeStartArgs, rangeEndArgs []interface{}, chunkSize int64, includeRangeStartValues bool, hint string)

}

func BuildUniqueKeyRangeEndPreparedQueryViaOffset(databaseName, tableName string, uniqueKeyColumns *ColumnList, rangeStartArgs, rangeEndArgs []interface{}, chunkSize int64, includeRangeStartValues bool, hint string) (result string, explodedArgs []interface{}, err error) {
	if uniqueKeyColumns.Len() == 0 {
		return "", explodedArgs, fmt.Errorf("got 0 columns in BuildUniqueKeyRangeEndPreparedQuery")
	}
	databaseName = EscapeName(databaseName)
	tableName = EscapeName(tableName)

	var startRangeComparisonSign = GreaterThanComparisonSign
	if includeRangeStartValues {
		startRangeComparisonSign = GreaterThanOrEqualsComparisonSign
	}

	if uniqueKeyColumns.Len() == 2 {
		return buildUniqueKeyRangeEndTwoColumnViaOffset(databaseName, tableName, uniqueKeyColumns, rangeStartArgs, rangeEndArgs, chunkSize, startRangeComparisonSign, hint)
	}

	rangeStartComparison, rangeExplodedArgs, err := BuildRangePreparedComparison(uniqueKeyColumns, rangeStartArgs, startRangeComparisonSign)
	if err != nil {
		return "", explodedArgs, err
	}
	explodedArgs = append(explodedArgs, rangeExplodedArgs...)
	rangeEndComparison, rangeExplodedArgs, err := BuildRangePreparedComparison(uniqueKeyColumns, rangeEndArgs, LessThanOrEqualsComparisonSign)
	if err != nil {
		return "", explodedArgs, err
	}
	explodedArgs = append(explodedArgs, rangeExplodedArgs...)

	uniqueKeyColumnNames := duplicateNames(uniqueKeyColumns.Names())
	uniqueKeyColumnAscending := make([]string, len(uniqueKeyColumnNames))
	for i, column := range uniqueKeyColumns.Columns() {
		uniqueKeyColumnNames[i] = EscapeName(uniqueKeyColumnNames[i])
		if column.Type == EnumColumnType {
			uniqueKeyColumnAscending[i] = fmt.Sprintf("concat(%s) asc", uniqueKeyColumnNames[i])
		} else {
			uniqueKeyColumnAscending[i] = fmt.Sprintf("%s asc", uniqueKeyColumnNames[i])
		}
	}
	result = fmt.Sprintf(`
		select /* gh-ost %s.%s %s */
			%s
		from
			%s.%s
		where
			%s and %s
		order by
			%s
		limit 1
		offset %d`,
		databaseName, tableName, hint,
		strings.Join(uniqueKeyColumnNames, ", "),
		databaseName, tableName,
		rangeStartComparison, rangeEndComparison,
		strings.Join(uniqueKeyColumnAscending, ", "),
		(chunkSize - 1),
	)
	return result, explodedArgs, nil
}