go正则表达式
https://github.com/cookieY/Yearning/blob/ad6c04b2904bb4cdcb64f732ce088d072751074e/src/lib/toolbox.go#L237
| package soar | |
| import ( | |
| "errors" | |
| "fmt" | |
| "github.com/pingcap/parser" | |
| "github.com/pingcap/parser/ast" | |
| _ "github.com/pingcap/tidb/types/parser_driver" | |
| "log" | |
| "regexp" | |
| "strings" | |
| ) | |
| func MergeAlterTables(sql string) (string, error) { | |
| alterSQLs := make(map[string][]string) | |
| var mergedAlterStr string | |
| var nonSqls string | |
| // table/column/index name can be quoted in back ticks | |
| backTicks := "(`[^\\s]*`)" | |
| alterExp := regexp.MustCompile(`(?i)alter\s*table\s*(` + backTicks + `|([^\s]*))\s*`) // ALTER TABLE | |
| createIndexExp := regexp.MustCompile(`(?i)create((unique)|(fulltext)|(spatial)|(primary)|(\s*)\s*)((index)|(key))\s*`) | |
| renameExp := regexp.MustCompile(`(?i)rename\s*table\s*(` + backTicks + `|([^\s]*))\s*`) // RENAME TABLE | |
| indexNameExp := regexp.MustCompile(`(?i)(` + backTicks + `|([^\s]*))\s*`) | |
| indexColsExp := regexp.MustCompile(`(?i)(` + backTicks + `|([^\s]*))\s*on\s*(` + backTicks + `|([^\s]*))\s*`) | |
| p := parser.New() | |
| stmt, _, err := p.Parse(sql, "", "") | |
| if err != nil { | |
| return "", errors.New(err.Error()) | |
| } | |
| for _, idx := range stmt { | |
| alterSQL := "" | |
| dbName := "" | |
| tableName := "" | |
| switch n := idx.(type) { | |
| case *ast.AlterTableStmt: | |
| sols := strings.Trim(n.Text(), ";") | |
| tableName = n.Table.Name.L | |
| dbName = n.Table.Schema.L | |
| if alterExp.MatchString(sols) { | |
| alterSQL = fmt.Sprint(alterExp.ReplaceAllString(sols, "")) | |
| } else if createIndexExp.MatchString(sols) { | |
| buf := createIndexExp.ReplaceAllString(sols, "") | |
| idxName := strings.TrimSpace(indexNameExp.FindString(buf)) | |
| buf = indexColsExp.ReplaceAllString(buf, "") | |
| alterSQL = fmt.Sprint("ADD INDEX", " "+idxName+" ", buf) | |
| } | |
| case *ast.RenameTableStmt: | |
| sols := strings.Trim(n.Text(), ";") | |
| if alterExp.MatchString(sols) { | |
| alterSQL = fmt.Sprint(alterExp.ReplaceAllString(sols, "")) | |
| } else if renameExp.MatchString(sols) { | |
| alterSQL = fmt.Sprint(alterExp.ReplaceAllString(sols, "")) | |
| } else { | |
| log.Printf("rename not match: %v", n.Text()) | |
| } | |
| default: | |
| nonSqls += n.Text() + "\n" | |
| } | |
| if alterSQL != "" && tableName != "" && tableName != "dual" { | |
| if dbName == "" { | |
| alterSQLs["`"+tableName+"`"] = append(alterSQLs["`"+tableName+"`"], alterSQL) | |
| } else { | |
| alterSQLs["`"+dbName+"`.`"+tableName+"`"] = append(alterSQLs["`"+dbName+"`.`"+tableName+"`"], alterSQL) | |
| } | |
| } | |
| } | |
| for k, v := range alterSQLs { | |
| mergedAlterStr += fmt.Sprintln("ALTER TABLE", k, strings.Join(v, ", "), ";") | |
| } | |
| mergedAlterStr += nonSqls | |
| return mergedAlterStr, nil | |
| } |
