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// Copyright 2019 The Xorm Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package dialects
import (
"context"
"fmt"
"strings"
"time"
"xorm.io/xorm/core"
"xorm.io/xorm/schemas"
)
// URI represents an uri to visit database
type URI struct {
DBType schemas.DBType
Proto string
Host string
Port string
DBName string
User string
Passwd string
Charset string
Laddr string
Raddr string
Timeout time.Duration
Schema string
}
// SetSchema set schema
func (uri *URI) SetSchema(schema string) {
// hack me
if uri.DBType == schemas.POSTGRES {
uri.Schema = strings.TrimSpace(schema)
}
}
const (
IncrAutoincrMode = iota
SequenceAutoincrMode
)
type DialectFeatures struct {
AutoincrMode int // 0 autoincrement column, 1 sequence
}
// Dialect represents a kind of database
type Dialect interface {
Init(*URI) error
URI() *URI
Version(ctx context.Context, queryer core.Queryer) (*schemas.Version, error)
Features() *DialectFeatures
SQLType(*schemas.Column) string
Alias(string) string // return what a sql type's alias of
ColumnTypeKind(string) int // database column type kind
IsReserved(string) bool
Quoter() schemas.Quoter
SetQuotePolicy(quotePolicy QuotePolicy)
AutoIncrStr() string
GetIndexes(queryer core.Queryer, ctx context.Context, tableName string) (map[string]*schemas.Index, error)
IndexCheckSQL(tableName, idxName string) (string, []interface{})
CreateIndexSQL(tableName string, index *schemas.Index) string
DropIndexSQL(tableName string, index *schemas.Index) string
GetTables(queryer core.Queryer, ctx context.Context) ([]*schemas.Table, error)
IsTableExist(queryer core.Queryer, ctx context.Context, tableName string) (bool, error)
CreateTableSQL(ctx context.Context, queryer core.Queryer, table *schemas.Table, tableName string) (string, bool, error)
DropTableSQL(tableName string) (string, bool)
CreateSequenceSQL(ctx context.Context, queryer core.Queryer, seqName string) (string, error)
IsSequenceExist(ctx context.Context, queryer core.Queryer, seqName string) (bool, error)
DropSequenceSQL(seqName string) (string, error)
GetColumns(queryer core.Queryer, ctx context.Context, tableName string) ([]string, map[string]*schemas.Column, error)
IsColumnExist(queryer core.Queryer, ctx context.Context, tableName string, colName string) (bool, error)
AddColumnSQL(tableName string, col *schemas.Column) string
ModifyColumnSQL(tableName string, col *schemas.Column) string
ForUpdateSQL(query string) string
Filters() []Filter
SetParams(params map[string]string)
}
// Base represents a basic dialect and all real dialects could embed this struct
type Base struct {
dialect Dialect
uri *URI
quoter schemas.Quoter
}
// Alias returned col itself
func (db *Base) Alias(col string) string {
return col
}
// Quoter returns the current database Quoter
func (db *Base) Quoter() schemas.Quoter {
return db.quoter
}
// Init initialize the dialect
func (db *Base) Init(dialect Dialect, uri *URI) error {
db.dialect, db.uri = dialect, uri
return nil
}
// URI returns the uri of database
func (db *Base) URI() *URI {
return db.uri
}
// CreateTableSQL implements Dialect
func (db *Base) CreateTableSQL(ctx context.Context, queryer core.Queryer, table *schemas.Table, tableName string) (string, bool, error) {
if tableName == "" {
tableName = table.Name
}
quoter := db.dialect.Quoter()
var b strings.Builder
b.WriteString("CREATE TABLE IF NOT EXISTS ")
quoter.QuoteTo(&b, tableName)
b.WriteString(" (")
for i, colName := range table.ColumnsSeq() {
col := table.GetColumn(colName)
s, _ := ColumnString(db.dialect, col, col.IsPrimaryKey && len(table.PrimaryKeys) == 1)
b.WriteString(s)
if i != len(table.ColumnsSeq())-1 {
b.WriteString(", ")
}
}
if len(table.PrimaryKeys) > 1 {
b.WriteString(", PRIMARY KEY (")
b.WriteString(quoter.Join(table.PrimaryKeys, ","))
b.WriteString(")")
}
b.WriteString(")")
return b.String(), false, nil
}
func (db *Base) CreateSequenceSQL(ctx context.Context, queryer core.Queryer, seqName string) (string, error) {
return fmt.Sprintf(`CREATE SEQUENCE %s
minvalue 1
nomaxvalue
start with 1
increment by 1
nocycle
nocache`, seqName), nil
}
func (db *Base) IsSequenceExist(ctx context.Context, queryer core.Queryer, seqName string) (bool, error) {
return false, fmt.Errorf("unsupported sequence feature")
}
func (db *Base) DropSequenceSQL(seqName string) (string, error) {
return fmt.Sprintf("DROP SEQUENCE %s", seqName), nil
}
// DropTableSQL returns drop table SQL
func (db *Base) DropTableSQL(tableName string) (string, bool) {
quote := db.dialect.Quoter().Quote
return fmt.Sprintf("DROP TABLE IF EXISTS %s", quote(tableName)), true
}
// HasRecords returns true if the SQL has records returned
func (db *Base) HasRecords(queryer core.Queryer, ctx context.Context, query string, args ...interface{}) (bool, error) {
rows, err := queryer.QueryContext(ctx, query, args...)
if err != nil {
return false, err
}
defer rows.Close()
if rows.Next() {
return true, nil
}
return false, rows.Err()
}
// IsColumnExist returns true if the column of the table exist
func (db *Base) IsColumnExist(queryer core.Queryer, ctx context.Context, tableName, colName string) (bool, error) {
quote := db.dialect.Quoter().Quote
query := fmt.Sprintf(
"SELECT %v FROM %v.%v WHERE %v = ? AND %v = ? AND %v = ?",
quote("COLUMN_NAME"),
quote("INFORMATION_SCHEMA"),
quote("COLUMNS"),
quote("TABLE_SCHEMA"),
quote("TABLE_NAME"),
quote("COLUMN_NAME"),
)
return db.HasRecords(queryer, ctx, query, db.uri.DBName, tableName, colName)
}
// AddColumnSQL returns a SQL to add a column
func (db *Base) AddColumnSQL(tableName string, col *schemas.Column) string {
s, _ := ColumnString(db.dialect, col, true)
return fmt.Sprintf("ALTER TABLE %s ADD %s", db.dialect.Quoter().Quote(tableName), s)
}
// CreateIndexSQL returns a SQL to create index
func (db *Base) CreateIndexSQL(tableName string, index *schemas.Index) string {
quoter := db.dialect.Quoter()
var unique string
var idxName string
if index.Type == schemas.UniqueType {
unique = " UNIQUE"
}
idxName = index.XName(tableName)
return fmt.Sprintf("CREATE%s INDEX %v ON %v (%v)", unique,
quoter.Quote(idxName), quoter.Quote(tableName),
quoter.Join(index.Cols, ","))
}
// DropIndexSQL returns a SQL to drop index
func (db *Base) DropIndexSQL(tableName string, index *schemas.Index) string {
quote := db.dialect.Quoter().Quote
var name string
if index.IsRegular {
name = index.XName(tableName)
} else {
name = index.Name
}
return fmt.Sprintf("DROP INDEX %v ON %s", quote(name), quote(tableName))
}
// ModifyColumnSQL returns a SQL to modify SQL
func (db *Base) ModifyColumnSQL(tableName string, col *schemas.Column) string {
s, _ := ColumnString(db.dialect, col, false)
return fmt.Sprintf("ALTER TABLE %s MODIFY COLUMN %s", db.quoter.Quote(tableName), s)
}
// ForUpdateSQL returns for updateSQL
func (db *Base) ForUpdateSQL(query string) string {
return query + " FOR UPDATE"
}
// SetParams set params
func (db *Base) SetParams(params map[string]string) {
}
var (
dialects = map[string]func() Dialect{}
)
// RegisterDialect register database dialect
func RegisterDialect(dbName schemas.DBType, dialectFunc func() Dialect) {
if dialectFunc == nil {
panic("core: Register dialect is nil")
}
dialects[strings.ToLower(string(dbName))] = dialectFunc // !nashtsai! allow override dialect
}
// QueryDialect query if registered database dialect
func QueryDialect(dbName schemas.DBType) Dialect {
if d, ok := dialects[strings.ToLower(string(dbName))]; ok {
return d()
}
return nil
}
func regDrvsNDialects() bool {
providedDrvsNDialects := map[string]struct {
dbType schemas.DBType
getDriver func() Driver
getDialect func() Dialect
}{
"mssql": {"mssql", func() Driver { return &odbcDriver{} }, func() Dialect { return &mssql{} }},
"odbc": {"mssql", func() Driver { return &odbcDriver{} }, func() Dialect { return &mssql{} }}, // !nashtsai! TODO change this when supporting MS Access
"mysql": {"mysql", func() Driver { return &mysqlDriver{} }, func() Dialect { return &mysql{} }},
"mymysql": {"mysql", func() Driver { return &mymysqlDriver{} }, func() Dialect { return &mysql{} }},
"postgres": {"postgres", func() Driver { return &pqDriver{} }, func() Dialect { return &postgres{} }},
"pgx": {"postgres", func() Driver { return &pqDriverPgx{} }, func() Dialect { return &postgres{} }},
"sqlite3": {"sqlite3", func() Driver { return &sqlite3Driver{} }, func() Dialect { return &sqlite3{} }},
"sqlite": {"sqlite3", func() Driver { return &sqlite3Driver{} }, func() Dialect { return &sqlite3{} }},
"oci8": {"oracle", func() Driver { return &oci8Driver{} }, func() Dialect { return &oracle{} }},
"godror": {"oracle", func() Driver { return &godrorDriver{} }, func() Dialect { return &oracle{} }},
}
for driverName, v := range providedDrvsNDialects {
if driver := QueryDriver(driverName); driver == nil {
RegisterDriver(driverName, v.getDriver())
RegisterDialect(v.dbType, v.getDialect)
}
}
return true
}
func init() {
regDrvsNDialects()
}
// ColumnString generate column description string according dialect
func ColumnString(dialect Dialect, col *schemas.Column, includePrimaryKey bool) (string, error) {
bd := strings.Builder{}
if err := dialect.Quoter().QuoteTo(&bd, col.Name); err != nil {
return "", err
}
if err := bd.WriteByte(' '); err != nil {
return "", err
}
if _, err := bd.WriteString(dialect.SQLType(col)); err != nil {
return "", err
}
if includePrimaryKey && col.IsPrimaryKey {
if _, err := bd.WriteString(" PRIMARY KEY"); err != nil {
return "", err
}
if col.IsAutoIncrement {
if err := bd.WriteByte(' '); err != nil {
return "", err
}
if _, err := bd.WriteString(dialect.AutoIncrStr()); err != nil {
return "", err
}
}
}
if !col.DefaultIsEmpty {
if _, err := bd.WriteString(" DEFAULT "); err != nil {
return "", err
}
if col.Default == "" {
if _, err := bd.WriteString("''"); err != nil {
return "", err
}
} else {
if _, err := bd.WriteString(col.Default); err != nil {
return "", err
}
}
}
if col.Nullable {
if _, err := bd.WriteString(" NULL"); err != nil {
return "", err
}
} else {
if _, err := bd.WriteString(" NOT NULL"); err != nil {
return "", err
}
}
return bd.String(), nil
}