vikunja-api/vendor/xorm.io/xorm/dialects/oracle.go
konrad d28f005552 Update xorm to v1 (#323)
Fix limit for databases other than sqlite

go mod tidy && go mod vendor

Remove unneeded break statements

Make everything work with the new xorm version

Fix xorm logging

Fix lint

Fix redis init

Fix using id field

Fix database init for testing

Change default database log level

Add xorm logger

Use const for postgres

go mod tidy

Merge branch 'master' into update/xorm

# Conflicts:
#	go.mod
#	go.sum
#	vendor/modules.txt

go mod vendor

Fix loading fixtures for postgres

Go mod vendor1

Update xorm to version 1

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/323
2020-04-12 17:29:24 +00:00

849 lines
27 KiB
Go

// Copyright 2015 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"
"errors"
"fmt"
"regexp"
"strconv"
"strings"
"xorm.io/xorm/core"
"xorm.io/xorm/schemas"
)
var (
oracleReservedWords = map[string]bool{
"ACCESS": true,
"ACCOUNT": true,
"ACTIVATE": true,
"ADD": true,
"ADMIN": true,
"ADVISE": true,
"AFTER": true,
"ALL": true,
"ALL_ROWS": true,
"ALLOCATE": true,
"ALTER": true,
"ANALYZE": true,
"AND": true,
"ANY": true,
"ARCHIVE": true,
"ARCHIVELOG": true,
"ARRAY": true,
"AS": true,
"ASC": true,
"AT": true,
"AUDIT": true,
"AUTHENTICATED": true,
"AUTHORIZATION": true,
"AUTOEXTEND": true,
"AUTOMATIC": true,
"BACKUP": true,
"BECOME": true,
"BEFORE": true,
"BEGIN": true,
"BETWEEN": true,
"BFILE": true,
"BITMAP": true,
"BLOB": true,
"BLOCK": true,
"BODY": true,
"BY": true,
"CACHE": true,
"CACHE_INSTANCES": true,
"CANCEL": true,
"CASCADE": true,
"CAST": true,
"CFILE": true,
"CHAINED": true,
"CHANGE": true,
"CHAR": true,
"CHAR_CS": true,
"CHARACTER": true,
"CHECK": true,
"CHECKPOINT": true,
"CHOOSE": true,
"CHUNK": true,
"CLEAR": true,
"CLOB": true,
"CLONE": true,
"CLOSE": true,
"CLOSE_CACHED_OPEN_CURSORS": true,
"CLUSTER": true,
"COALESCE": true,
"COLUMN": true,
"COLUMNS": true,
"COMMENT": true,
"COMMIT": true,
"COMMITTED": true,
"COMPATIBILITY": true,
"COMPILE": true,
"COMPLETE": true,
"COMPOSITE_LIMIT": true,
"COMPRESS": true,
"COMPUTE": true,
"CONNECT": true,
"CONNECT_TIME": true,
"CONSTRAINT": true,
"CONSTRAINTS": true,
"CONTENTS": true,
"CONTINUE": true,
"CONTROLFILE": true,
"CONVERT": true,
"COST": true,
"CPU_PER_CALL": true,
"CPU_PER_SESSION": true,
"CREATE": true,
"CURRENT": true,
"CURRENT_SCHEMA": true,
"CURREN_USER": true,
"CURSOR": true,
"CYCLE": true,
"DANGLING": true,
"DATABASE": true,
"DATAFILE": true,
"DATAFILES": true,
"DATAOBJNO": true,
"DATE": true,
"DBA": true,
"DBHIGH": true,
"DBLOW": true,
"DBMAC": true,
"DEALLOCATE": true,
"DEBUG": true,
"DEC": true,
"DECIMAL": true,
"DECLARE": true,
"DEFAULT": true,
"DEFERRABLE": true,
"DEFERRED": true,
"DEGREE": true,
"DELETE": true,
"DEREF": true,
"DESC": true,
"DIRECTORY": true,
"DISABLE": true,
"DISCONNECT": true,
"DISMOUNT": true,
"DISTINCT": true,
"DISTRIBUTED": true,
"DML": true,
"DOUBLE": true,
"DROP": true,
"DUMP": true,
"EACH": true,
"ELSE": true,
"ENABLE": true,
"END": true,
"ENFORCE": true,
"ENTRY": true,
"ESCAPE": true,
"EXCEPT": true,
"EXCEPTIONS": true,
"EXCHANGE": true,
"EXCLUDING": true,
"EXCLUSIVE": true,
"EXECUTE": true,
"EXISTS": true,
"EXPIRE": true,
"EXPLAIN": true,
"EXTENT": true,
"EXTENTS": true,
"EXTERNALLY": true,
"FAILED_LOGIN_ATTEMPTS": true,
"FALSE": true,
"FAST": true,
"FILE": true,
"FIRST_ROWS": true,
"FLAGGER": true,
"FLOAT": true,
"FLOB": true,
"FLUSH": true,
"FOR": true,
"FORCE": true,
"FOREIGN": true,
"FREELIST": true,
"FREELISTS": true,
"FROM": true,
"FULL": true,
"FUNCTION": true,
"GLOBAL": true,
"GLOBALLY": true,
"GLOBAL_NAME": true,
"GRANT": true,
"GROUP": true,
"GROUPS": true,
"HASH": true,
"HASHKEYS": true,
"HAVING": true,
"HEADER": true,
"HEAP": true,
"IDENTIFIED": true,
"IDGENERATORS": true,
"IDLE_TIME": true,
"IF": true,
"IMMEDIATE": true,
"IN": true,
"INCLUDING": true,
"INCREMENT": true,
"INDEX": true,
"INDEXED": true,
"INDEXES": true,
"INDICATOR": true,
"IND_PARTITION": true,
"INITIAL": true,
"INITIALLY": true,
"INITRANS": true,
"INSERT": true,
"INSTANCE": true,
"INSTANCES": true,
"INSTEAD": true,
"INT": true,
"INTEGER": true,
"INTERMEDIATE": true,
"INTERSECT": true,
"INTO": true,
"IS": true,
"ISOLATION": true,
"ISOLATION_LEVEL": true,
"KEEP": true,
"KEY": true,
"KILL": true,
"LABEL": true,
"LAYER": true,
"LESS": true,
"LEVEL": true,
"LIBRARY": true,
"LIKE": true,
"LIMIT": true,
"LINK": true,
"LIST": true,
"LOB": true,
"LOCAL": true,
"LOCK": true,
"LOCKED": true,
"LOG": true,
"LOGFILE": true,
"LOGGING": true,
"LOGICAL_READS_PER_CALL": true,
"LOGICAL_READS_PER_SESSION": true,
"LONG": true,
"MANAGE": true,
"MASTER": true,
"MAX": true,
"MAXARCHLOGS": true,
"MAXDATAFILES": true,
"MAXEXTENTS": true,
"MAXINSTANCES": true,
"MAXLOGFILES": true,
"MAXLOGHISTORY": true,
"MAXLOGMEMBERS": true,
"MAXSIZE": true,
"MAXTRANS": true,
"MAXVALUE": true,
"MIN": true,
"MEMBER": true,
"MINIMUM": true,
"MINEXTENTS": true,
"MINUS": true,
"MINVALUE": true,
"MLSLABEL": true,
"MLS_LABEL_FORMAT": true,
"MODE": true,
"MODIFY": true,
"MOUNT": true,
"MOVE": true,
"MTS_DISPATCHERS": true,
"MULTISET": true,
"NATIONAL": true,
"NCHAR": true,
"NCHAR_CS": true,
"NCLOB": true,
"NEEDED": true,
"NESTED": true,
"NETWORK": true,
"NEW": true,
"NEXT": true,
"NOARCHIVELOG": true,
"NOAUDIT": true,
"NOCACHE": true,
"NOCOMPRESS": true,
"NOCYCLE": true,
"NOFORCE": true,
"NOLOGGING": true,
"NOMAXVALUE": true,
"NOMINVALUE": true,
"NONE": true,
"NOORDER": true,
"NOOVERRIDE": true,
"NOPARALLEL": true,
"NOREVERSE": true,
"NORMAL": true,
"NOSORT": true,
"NOT": true,
"NOTHING": true,
"NOWAIT": true,
"NULL": true,
"NUMBER": true,
"NUMERIC": true,
"NVARCHAR2": true,
"OBJECT": true,
"OBJNO": true,
"OBJNO_REUSE": true,
"OF": true,
"OFF": true,
"OFFLINE": true,
"OID": true,
"OIDINDEX": true,
"OLD": true,
"ON": true,
"ONLINE": true,
"ONLY": true,
"OPCODE": true,
"OPEN": true,
"OPTIMAL": true,
"OPTIMIZER_GOAL": true,
"OPTION": true,
"OR": true,
"ORDER": true,
"ORGANIZATION": true,
"OSLABEL": true,
"OVERFLOW": true,
"OWN": true,
"PACKAGE": true,
"PARALLEL": true,
"PARTITION": true,
"PASSWORD": true,
"PASSWORD_GRACE_TIME": true,
"PASSWORD_LIFE_TIME": true,
"PASSWORD_LOCK_TIME": true,
"PASSWORD_REUSE_MAX": true,
"PASSWORD_REUSE_TIME": true,
"PASSWORD_VERIFY_FUNCTION": true,
"PCTFREE": true,
"PCTINCREASE": true,
"PCTTHRESHOLD": true,
"PCTUSED": true,
"PCTVERSION": true,
"PERCENT": true,
"PERMANENT": true,
"PLAN": true,
"PLSQL_DEBUG": true,
"POST_TRANSACTION": true,
"PRECISION": true,
"PRESERVE": true,
"PRIMARY": true,
"PRIOR": true,
"PRIVATE": true,
"PRIVATE_SGA": true,
"PRIVILEGE": true,
"PRIVILEGES": true,
"PROCEDURE": true,
"PROFILE": true,
"PUBLIC": true,
"PURGE": true,
"QUEUE": true,
"QUOTA": true,
"RANGE": true,
"RAW": true,
"RBA": true,
"READ": true,
"READUP": true,
"REAL": true,
"REBUILD": true,
"RECOVER": true,
"RECOVERABLE": true,
"RECOVERY": true,
"REF": true,
"REFERENCES": true,
"REFERENCING": true,
"REFRESH": true,
"RENAME": true,
"REPLACE": true,
"RESET": true,
"RESETLOGS": true,
"RESIZE": true,
"RESOURCE": true,
"RESTRICTED": true,
"RETURN": true,
"RETURNING": true,
"REUSE": true,
"REVERSE": true,
"REVOKE": true,
"ROLE": true,
"ROLES": true,
"ROLLBACK": true,
"ROW": true,
"ROWID": true,
"ROWNUM": true,
"ROWS": true,
"RULE": true,
"SAMPLE": true,
"SAVEPOINT": true,
"SB4": true,
"SCAN_INSTANCES": true,
"SCHEMA": true,
"SCN": true,
"SCOPE": true,
"SD_ALL": true,
"SD_INHIBIT": true,
"SD_SHOW": true,
"SEGMENT": true,
"SEG_BLOCK": true,
"SEG_FILE": true,
"SELECT": true,
"SEQUENCE": true,
"SERIALIZABLE": true,
"SESSION": true,
"SESSION_CACHED_CURSORS": true,
"SESSIONS_PER_USER": true,
"SET": true,
"SHARE": true,
"SHARED": true,
"SHARED_POOL": true,
"SHRINK": true,
"SIZE": true,
"SKIP": true,
"SKIP_UNUSABLE_INDEXES": true,
"SMALLINT": true,
"SNAPSHOT": true,
"SOME": true,
"SORT": true,
"SPECIFICATION": true,
"SPLIT": true,
"SQL_TRACE": true,
"STANDBY": true,
"START": true,
"STATEMENT_ID": true,
"STATISTICS": true,
"STOP": true,
"STORAGE": true,
"STORE": true,
"STRUCTURE": true,
"SUCCESSFUL": true,
"SWITCH": true,
"SYS_OP_ENFORCE_NOT_NULL$": true,
"SYS_OP_NTCIMG$": true,
"SYNONYM": true,
"SYSDATE": true,
"SYSDBA": true,
"SYSOPER": true,
"SYSTEM": true,
"TABLE": true,
"TABLES": true,
"TABLESPACE": true,
"TABLESPACE_NO": true,
"TABNO": true,
"TEMPORARY": true,
"THAN": true,
"THE": true,
"THEN": true,
"THREAD": true,
"TIMESTAMP": true,
"TIME": true,
"TO": true,
"TOPLEVEL": true,
"TRACE": true,
"TRACING": true,
"TRANSACTION": true,
"TRANSITIONAL": true,
"TRIGGER": true,
"TRIGGERS": true,
"TRUE": true,
"TRUNCATE": true,
"TX": true,
"TYPE": true,
"UB2": true,
"UBA": true,
"UID": true,
"UNARCHIVED": true,
"UNDO": true,
"UNION": true,
"UNIQUE": true,
"UNLIMITED": true,
"UNLOCK": true,
"UNRECOVERABLE": true,
"UNTIL": true,
"UNUSABLE": true,
"UNUSED": true,
"UPDATABLE": true,
"UPDATE": true,
"USAGE": true,
"USE": true,
"USER": true,
"USING": true,
"VALIDATE": true,
"VALIDATION": true,
"VALUE": true,
"VALUES": true,
"VARCHAR": true,
"VARCHAR2": true,
"VARYING": true,
"VIEW": true,
"WHEN": true,
"WHENEVER": true,
"WHERE": true,
"WITH": true,
"WITHOUT": true,
"WORK": true,
"WRITE": true,
"WRITEDOWN": true,
"WRITEUP": true,
"XID": true,
"YEAR": true,
"ZONE": true,
}
oracleQuoter = schemas.Quoter{'[', ']', schemas.AlwaysReserve}
)
type oracle struct {
Base
}
func (db *oracle) Init(uri *URI) error {
db.quoter = oracleQuoter
return db.Base.Init(db, uri)
}
func (db *oracle) SQLType(c *schemas.Column) string {
var res string
switch t := c.SQLType.Name; t {
case schemas.Bit, schemas.TinyInt, schemas.SmallInt, schemas.MediumInt, schemas.Int, schemas.Integer, schemas.BigInt, schemas.Bool, schemas.Serial, schemas.BigSerial:
res = "NUMBER"
case schemas.Binary, schemas.VarBinary, schemas.Blob, schemas.TinyBlob, schemas.MediumBlob, schemas.LongBlob, schemas.Bytea:
return schemas.Blob
case schemas.Time, schemas.DateTime, schemas.TimeStamp:
res = schemas.TimeStamp
case schemas.TimeStampz:
res = "TIMESTAMP WITH TIME ZONE"
case schemas.Float, schemas.Double, schemas.Numeric, schemas.Decimal:
res = "NUMBER"
case schemas.Text, schemas.MediumText, schemas.LongText, schemas.Json:
res = "CLOB"
case schemas.Char, schemas.Varchar, schemas.TinyText:
res = "VARCHAR2"
default:
res = t
}
hasLen1 := (c.Length > 0)
hasLen2 := (c.Length2 > 0)
if hasLen2 {
res += "(" + strconv.Itoa(c.Length) + "," + strconv.Itoa(c.Length2) + ")"
} else if hasLen1 {
res += "(" + strconv.Itoa(c.Length) + ")"
}
return res
}
func (db *oracle) AutoIncrStr() string {
return "AUTO_INCREMENT"
}
func (db *oracle) IsReserved(name string) bool {
_, ok := oracleReservedWords[strings.ToUpper(name)]
return ok
}
func (db *oracle) DropTableSQL(tableName string) (string, bool) {
return fmt.Sprintf("DROP TABLE `%s`", tableName), false
}
func (db *oracle) CreateTableSQL(table *schemas.Table, tableName string) ([]string, bool) {
var sql = "CREATE TABLE "
if tableName == "" {
tableName = table.Name
}
quoter := db.Quoter()
sql += quoter.Quote(tableName) + " ("
pkList := table.PrimaryKeys
for _, colName := range table.ColumnsSeq() {
col := table.GetColumn(colName)
/*if col.IsPrimaryKey && len(pkList) == 1 {
sql += col.String(b.dialect)
} else {*/
sql += db.StringNoPk(col)
// }
sql = strings.TrimSpace(sql)
sql += ", "
}
if len(pkList) > 0 {
sql += "PRIMARY KEY ( "
sql += quoter.Join(pkList, ",")
sql += " ), "
}
sql = sql[:len(sql)-2] + ")"
return []string{sql}, false
}
func (db *oracle) SetQuotePolicy(quotePolicy QuotePolicy) {
switch quotePolicy {
case QuotePolicyNone:
var q = oracleQuoter
q.IsReserved = schemas.AlwaysNoReserve
db.quoter = q
case QuotePolicyReserved:
var q = oracleQuoter
q.IsReserved = db.IsReserved
db.quoter = q
case QuotePolicyAlways:
fallthrough
default:
db.quoter = oracleQuoter
}
}
func (db *oracle) IndexCheckSQL(tableName, idxName string) (string, []interface{}) {
args := []interface{}{tableName, idxName}
return `SELECT INDEX_NAME FROM USER_INDEXES ` +
`WHERE TABLE_NAME = :1 AND INDEX_NAME = :2`, args
}
func (db *oracle) IsTableExist(queryer core.Queryer, ctx context.Context, tableName string) (bool, error) {
return db.HasRecords(queryer, ctx, `SELECT table_name FROM user_tables WHERE table_name = :1`, tableName)
}
func (db *oracle) IsColumnExist(queryer core.Queryer, ctx context.Context, tableName, colName string) (bool, error) {
args := []interface{}{tableName, colName}
query := "SELECT column_name FROM USER_TAB_COLUMNS WHERE table_name = :1" +
" AND column_name = :2"
return db.HasRecords(queryer, ctx, query, args...)
}
func (db *oracle) GetColumns(queryer core.Queryer, ctx context.Context, tableName string) ([]string, map[string]*schemas.Column, error) {
args := []interface{}{tableName}
s := "SELECT column_name,data_default,data_type,data_length,data_precision,data_scale," +
"nullable FROM USER_TAB_COLUMNS WHERE table_name = :1"
rows, err := queryer.QueryContext(ctx, s, args...)
if err != nil {
return nil, nil, err
}
defer rows.Close()
cols := make(map[string]*schemas.Column)
colSeq := make([]string, 0)
for rows.Next() {
col := new(schemas.Column)
col.Indexes = make(map[string]int)
var colName, colDefault, nullable, dataType, dataPrecision, dataScale *string
var dataLen int
err = rows.Scan(&colName, &colDefault, &dataType, &dataLen, &dataPrecision,
&dataScale, &nullable)
if err != nil {
return nil, nil, err
}
col.Name = strings.Trim(*colName, `" `)
if colDefault != nil {
col.Default = *colDefault
col.DefaultIsEmpty = false
}
if *nullable == "Y" {
col.Nullable = true
} else {
col.Nullable = false
}
var ignore bool
var dt string
var len1, len2 int
dts := strings.Split(*dataType, "(")
dt = dts[0]
if len(dts) > 1 {
lens := strings.Split(dts[1][:len(dts[1])-1], ",")
if len(lens) > 1 {
len1, _ = strconv.Atoi(lens[0])
len2, _ = strconv.Atoi(lens[1])
} else {
len1, _ = strconv.Atoi(lens[0])
}
}
switch dt {
case "VARCHAR2":
col.SQLType = schemas.SQLType{Name: schemas.Varchar, DefaultLength: len1, DefaultLength2: len2}
case "NVARCHAR2":
col.SQLType = schemas.SQLType{Name: schemas.NVarchar, DefaultLength: len1, DefaultLength2: len2}
case "TIMESTAMP WITH TIME ZONE":
col.SQLType = schemas.SQLType{Name: schemas.TimeStampz, DefaultLength: 0, DefaultLength2: 0}
case "NUMBER":
col.SQLType = schemas.SQLType{Name: schemas.Double, DefaultLength: len1, DefaultLength2: len2}
case "LONG", "LONG RAW":
col.SQLType = schemas.SQLType{Name: schemas.Text, DefaultLength: 0, DefaultLength2: 0}
case "RAW":
col.SQLType = schemas.SQLType{Name: schemas.Binary, DefaultLength: 0, DefaultLength2: 0}
case "ROWID":
col.SQLType = schemas.SQLType{Name: schemas.Varchar, DefaultLength: 18, DefaultLength2: 0}
case "AQ$_SUBSCRIBERS":
ignore = true
default:
col.SQLType = schemas.SQLType{Name: strings.ToUpper(dt), DefaultLength: len1, DefaultLength2: len2}
}
if ignore {
continue
}
if _, ok := schemas.SqlTypes[col.SQLType.Name]; !ok {
return nil, nil, fmt.Errorf("Unknown colType %v %v", *dataType, col.SQLType)
}
col.Length = dataLen
if col.SQLType.IsText() || col.SQLType.IsTime() {
if !col.DefaultIsEmpty {
col.Default = "'" + col.Default + "'"
}
}
cols[col.Name] = col
colSeq = append(colSeq, col.Name)
}
return colSeq, cols, nil
}
func (db *oracle) GetTables(queryer core.Queryer, ctx context.Context) ([]*schemas.Table, error) {
args := []interface{}{}
s := "SELECT table_name FROM user_tables"
rows, err := queryer.QueryContext(ctx, s, args...)
if err != nil {
return nil, err
}
defer rows.Close()
tables := make([]*schemas.Table, 0)
for rows.Next() {
table := schemas.NewEmptyTable()
err = rows.Scan(&table.Name)
if err != nil {
return nil, err
}
tables = append(tables, table)
}
return tables, nil
}
func (db *oracle) GetIndexes(queryer core.Queryer, ctx context.Context, tableName string) (map[string]*schemas.Index, error) {
args := []interface{}{tableName}
s := "SELECT t.column_name,i.uniqueness,i.index_name FROM user_ind_columns t,user_indexes i " +
"WHERE t.index_name = i.index_name and t.table_name = i.table_name and t.table_name =:1"
rows, err := queryer.QueryContext(ctx, s, args...)
if err != nil {
return nil, err
}
defer rows.Close()
indexes := make(map[string]*schemas.Index, 0)
for rows.Next() {
var indexType int
var indexName, colName, uniqueness string
err = rows.Scan(&colName, &uniqueness, &indexName)
if err != nil {
return nil, err
}
indexName = strings.Trim(indexName, `" `)
var isRegular bool
if strings.HasPrefix(indexName, "IDX_"+tableName) || strings.HasPrefix(indexName, "UQE_"+tableName) {
indexName = indexName[5+len(tableName):]
isRegular = true
}
if uniqueness == "UNIQUE" {
indexType = schemas.UniqueType
} else {
indexType = schemas.IndexType
}
var index *schemas.Index
var ok bool
if index, ok = indexes[indexName]; !ok {
index = new(schemas.Index)
index.Type = indexType
index.Name = indexName
index.IsRegular = isRegular
indexes[indexName] = index
}
index.AddColumn(colName)
}
return indexes, nil
}
func (db *oracle) Filters() []Filter {
return []Filter{
&SeqFilter{Prefix: ":", Start: 1},
}
}
type goracleDriver struct {
}
func (cfg *goracleDriver) Parse(driverName, dataSourceName string) (*URI, error) {
db := &URI{DBType: schemas.ORACLE}
dsnPattern := regexp.MustCompile(
`^(?:(?P<user>.*?)(?::(?P<passwd>.*))?@)?` + // [user[:password]@]
`(?:(?P<net>[^\(]*)(?:\((?P<addr>[^\)]*)\))?)?` + // [net[(addr)]]
`\/(?P<dbname>.*?)` + // /dbname
`(?:\?(?P<params>[^\?]*))?$`) // [?param1=value1&paramN=valueN]
matches := dsnPattern.FindStringSubmatch(dataSourceName)
// tlsConfigRegister := make(map[string]*tls.Config)
names := dsnPattern.SubexpNames()
for i, match := range matches {
switch names[i] {
case "dbname":
db.DBName = match
}
}
if db.DBName == "" {
return nil, errors.New("dbname is empty")
}
return db, nil
}
type oci8Driver struct {
}
// dataSourceName=user/password@ipv4:port/dbname
// dataSourceName=user/password@[ipv6]:port/dbname
func (p *oci8Driver) Parse(driverName, dataSourceName string) (*URI, error) {
db := &URI{DBType: schemas.ORACLE}
dsnPattern := regexp.MustCompile(
`^(?P<user>.*)\/(?P<password>.*)@` + // user:password@
`(?P<net>.*)` + // ip:port
`\/(?P<dbname>.*)`) // dbname
matches := dsnPattern.FindStringSubmatch(dataSourceName)
names := dsnPattern.SubexpNames()
for i, match := range matches {
switch names[i] {
case "dbname":
db.DBName = match
}
}
if db.DBName == "" && len(matches) != 0 {
return nil, errors.New("dbname is empty")
}
return db, nil
}