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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)
}
}
// Dialect represents a kind of database
type Dialect interface {
Init(*URI) error
URI() *URI
SQLType(*schemas.Column) string
FormatBytes(b []byte) string
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(table *schemas.Table, tableName string) ([]string, bool)
DropTableSQL(tableName string) (string, bool)
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
}
func (b *Base) Quoter() schemas.Quoter {
return b.quoter
}
func (b *Base) Init(dialect Dialect, uri *URI) error {
b.dialect, b.uri = dialect, uri
return nil
}
func (b *Base) URI() *URI {
return b.uri
}
func (b *Base) DBType() schemas.DBType {
return b.uri.DBType
}
func (b *Base) FormatBytes(bs []byte) string {
return fmt.Sprintf("0x%x", bs)
}
func (db *Base) DropTableSQL(tableName string) (string, bool) {
quote := db.dialect.Quoter().Quote
return fmt.Sprintf("DROP TABLE IF EXISTS %s", quote(tableName)), true
}
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, nil
}
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)
}
func (db *Base) AddColumnSQL(tableName string, col *schemas.Column) string {
s, _ := ColumnString(db.dialect, col, true)
return fmt.Sprintf("ALTER TABLE %v ADD %v", db.dialect.Quoter().Quote(tableName), s)
}
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, ","))
}
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))
}
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", tableName, s)
}
func (b *Base) ForUpdateSQL(query string) string {
return query + " FOR UPDATE"
}
func (b *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{} }},
"oci8": {"oracle", func() Driver { return &oci8Driver{} }, func() Dialect { return &oracle{} }},
"goracle": {"oracle", func() Driver { return &goracleDriver{} }, 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 err := bd.WriteByte(' '); err != nil {
return "", err
}
if includePrimaryKey && col.IsPrimaryKey {
if _, err := bd.WriteString("PRIMARY KEY "); err != nil {
return "", err
}
if col.IsAutoIncrement {
if _, err := bd.WriteString(dialect.AutoIncrStr()); err != nil {
return "", err
}
if err := bd.WriteByte(' '); err != nil {
return "", err
}
}
}
if col.Default != "" {
if _, err := bd.WriteString("DEFAULT "); err != nil {
return "", err
}
if _, err := bd.WriteString(col.Default); err != nil {
return "", err
}
if err := bd.WriteByte(' '); 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
}