jet/sqlbuilder/column.go
2019-06-04 12:10:23 +02:00

122 lines
2.1 KiB
Go

// Modeling of columns
package sqlbuilder
import (
"strings"
)
type column interface {
Expression
Name() string
TableName() string
DefaultAlias() projection
// Internal function for tracking tableName that a column belongs to
// for the purpose of serialization
setTableName(table string)
}
type NullableColumn bool
const (
Nullable NullableColumn = true
NotNullable NullableColumn = false
)
type Collation string
const (
UTF8CaseInsensitive Collation = "utf8_unicode_ci"
UTF8CaseSensitive Collation = "utf8_unicode"
UTF8Binary Collation = "utf8_bin"
)
// Representation of MySQL charsets
type Charset string
const (
UTF8 Charset = "utf8"
)
// The base type for real materialized columns.
type baseColumn struct {
expressionInterfaceImpl
name string
nullable NullableColumn
tableName string
}
func newBaseColumn(name string, nullable NullableColumn, tableName string, parent column) baseColumn {
bc := baseColumn{
name: name,
nullable: nullable,
tableName: tableName,
}
bc.expressionInterfaceImpl.parent = parent
return bc
}
func (c *baseColumn) Name() string {
return c.name
}
func (c *baseColumn) TableName() string {
return c.tableName
}
func (c *baseColumn) setTableName(table string) {
c.tableName = table
}
func (c *baseColumn) DefaultAlias() projection {
return c.AS(c.tableName + "." + c.name)
}
func (c *baseColumn) serializeAsOrderBy(statement statementType, out *queryData) error {
if statement == set_statement {
// set Statement (UNION, EXCEPT ...) can reference only select projections in order by clause
columnRef := ""
if c.tableName != "" {
columnRef += c.tableName + "."
}
columnRef += c.name
out.writeString(`"` + columnRef + `"`)
return nil
}
return c.serialize(statement, out)
}
func (c baseColumn) serialize(statement statementType, out *queryData, options ...serializeOption) error {
columnRef := ""
if c.tableName != "" {
columnRef += c.tableName + "."
}
wrapColumnName := strings.Contains(c.name, ".")
if wrapColumnName {
columnRef += `"`
}
columnRef += c.name
if wrapColumnName {
columnRef += `"`
}
out.writeString(columnRef)
return nil
}