示例#1
0
// newSourceInfoForSingleTable creates a simple dataSourceInfo
// which maps the same tableAlias to all columns.
func newSourceInfoForSingleTable(tn parser.TableName, columns []ResultColumn) *dataSourceInfo {
	norm := sqlbase.NormalizeTableName(tn)
	return &dataSourceInfo{
		sourceColumns: columns,
		sourceAliases: sourceAliases{norm: fillColumnRange(0, len(columns)-1)},
	}
}
示例#2
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// findUnaliasedColumn looks up the column specified by a VarName, not
// taking column renames into account (but table renames will be taken
// into account). That is, given a table "blah" with single column "y",
// findUnaliasedColumn("y") returns a valid index even in the context
// of:
//     SELECT * FROM blah as foo(x)
// If the VarName specifies a table name, only columns that have that
// name as their source alias are considered. If the VarName does not
// specify a table name, all columns in the data source are
// considered.  If no column is found, invalidColIdx is returned with
// no error.
func (p *planDataSource) findUnaliasedColumn(
	c *parser.ColumnItem,
) (colIdx int, err error) {
	colName := sqlbase.NormalizeName(c.ColumnName)
	tableName := sqlbase.NormalizeTableName(c.TableName)

	if tableName.Table() != "" {
		tn, err := p.info.checkDatabaseName(tableName)
		if err != nil {
			return invalidColIdx, nil
		}
		tableName = tn
	}

	colIdx = invalidColIdx
	planColumns := p.plan.Columns()

	selCol := func(colIdx int, idx int) (int, error) {
		col := planColumns[idx]
		if sqlbase.ReNormalizeName(col.Name) == colName {
			if colIdx != invalidColIdx {
				return invalidColIdx, fmt.Errorf("column reference \"%s\" is ambiguous", parser.AsString(c))
			}
			colIdx = idx
		}
		return colIdx, nil
	}

	if tableName.Table() == "" {
		for idx := 0; idx < len(p.info.sourceColumns); idx++ {
			colIdx, err = selCol(colIdx, idx)
			if err != nil {
				return colIdx, err
			}
		}
	} else {
		colRange, ok := p.info.sourceAliases[tableName]
		if !ok {
			// A table name is specified, but there is no column with this
			// table name.
			return invalidColIdx, nil
		}
		for _, idx := range colRange {
			colIdx, err = selCol(colIdx, idx)
			if err != nil {
				return colIdx, err
			}
		}
	}

	return colIdx, nil
}
示例#3
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// expandStar returns the array of column metadata and name
// expressions that correspond to the expansion of a star.
func (src *dataSourceInfo) expandStar(
	v parser.VarName, qvals qvalMap,
) (columns []ResultColumn, exprs []parser.TypedExpr, err error) {
	if len(src.sourceColumns) == 0 {
		return nil, nil, fmt.Errorf("cannot use \"%s\" without a FROM clause", v)
	}

	colSel := func(idx int) {
		col := src.sourceColumns[idx]
		if !col.hidden {
			qval := qvals.getQVal(columnRef{src, idx})
			columns = append(columns, ResultColumn{Name: col.Name, Typ: qval.datum})
			exprs = append(exprs, qval)
		}
	}

	tableName := parser.TableName{}
	if a, ok := v.(*parser.AllColumnsSelector); ok {
		tableName = a.TableName
	}
	if tableName.Table() == "" {
		for i := 0; i < len(src.sourceColumns); i++ {
			colSel(i)
		}
	} else {
		norm := sqlbase.NormalizeTableName(tableName)

		qualifiedTn, err := src.checkDatabaseName(norm)
		if err != nil {
			return nil, nil, err
		}

		colRange, ok := src.sourceAliases[qualifiedTn]
		if !ok {
			return nil, nil, fmt.Errorf("table %q not found", tableName.String())
		}
		for _, i := range colRange {
			colSel(i)
		}
	}

	return columns, exprs, nil
}
示例#4
0
// findColumn looks up the column specified by a VarName. The normalized VarName
// is returned.
func (sources multiSourceInfo) findColumn(
	c *parser.ColumnItem,
) (info *dataSourceInfo, colIdx int, err error) {
	if len(c.Selector) > 0 {
		return nil, invalidColIdx, util.UnimplementedWithIssueErrorf(8318, "compound types not supported yet: %q", c)
	}

	colName := sqlbase.NormalizeName(c.ColumnName)
	var tableName parser.TableName
	if c.TableName.Table() != "" {
		tableName = sqlbase.NormalizeTableName(c.TableName)

		tn, err := sources.checkDatabaseName(tableName)
		if err != nil {
			return nil, invalidColIdx, err
		}
		tableName = tn

		// Propagate the discovered database name back to the original VarName.
		// (to clarify the output of e.g. EXPLAIN)
		c.TableName.DatabaseName = tableName.DatabaseName
	}

	colIdx = invalidColIdx
	for _, src := range sources {
		findCol := func(src, info *dataSourceInfo, colIdx int, idx int) (*dataSourceInfo, int, error) {
			col := src.sourceColumns[idx]
			if sqlbase.ReNormalizeName(col.Name) == colName {
				if colIdx != invalidColIdx {
					return nil, invalidColIdx, fmt.Errorf("column reference %q is ambiguous", c)
				}
				info = src
				colIdx = idx
			}
			return info, colIdx, nil
		}

		if tableName.Table() == "" {
			for idx := 0; idx < len(src.sourceColumns); idx++ {
				info, colIdx, err = findCol(src, info, colIdx, idx)
				if err != nil {
					return info, colIdx, err
				}
			}
		} else {
			colRange, ok := src.sourceAliases[tableName]
			if !ok {
				// The data source "src" has no column for table tableName.
				// Try again with the net one.
				continue
			}
			for _, idx := range colRange {
				info, colIdx, err = findCol(src, info, colIdx, idx)
				if err != nil {
					return info, colIdx, err
				}
			}
		}
	}

	if colIdx == invalidColIdx {
		return nil, invalidColIdx, fmt.Errorf("column name %q not found", c)
	}

	return info, colIdx, nil
}