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go - gorose 不能创建超过 max_prepared_stmt_count 个语句

问题描述

我将 gorose 用于带有 golang 的 Web 项目，代码如下

var tablecheckrequest = "checkrequest"

func (mysqldao *MysqlDao) GetAllCheckRulesByRequestId(id int) []map[string]interface{} {
    result, _ := mysqldao.connection.Table(tablecheckrequest).
    Where("requestid", "=", id).Get()
    return result
}

一段时间后我明白了

不能创建超过 max_prepared_stmt_count 个语句（当前值：16382）

为什么会发生此错误？

标签： go

解决方案

我终于知道了！有gorose的源码

func (dba *Database) Execute(args ...interface{}) (int64, error) {
//defer DB.Close()
lenArgs := len(args)
var sqlstring string
var vals []interface{}

sqlstring = args[0].(string)

if lenArgs > 1 {
    for k, v := range args {
        if k > 0 {
            vals = append(vals, v)
        }
    }
}
// 记录sqllog
//Connect.SqlLog = append(Connect.SqlLog, fmt.Sprintf(sqlstring, vals...))
dba.LastSql = fmt.Sprintf(sqlstring, vals...)
dba.SqlLogs = append(dba.SqlLogs, dba.LastSql)

var operType string = strings.ToLower(sqlstring[0:6])
if operType == "select" {
    return 0, errors.New("this method does not allow select operations, use Query")
}

if dba.trans == true {
    stmt, err := tx.Prepare(sqlstring)
    if err != nil {
        return 0, err
    }
    return dba.parseExecute(stmt, operType, vals)
}

stmt, err := DB.Prepare(sqlstring)
if err != nil {
    return 0, err
}
return dba.parseExecute(stmt, operType, vals)
}

在此方法中，已创建 stmt 但从未关闭！要修复它，我们只需要添加一个 defer stmt.close() 过程中的方法 parseExecute() 就像

func (dba *Database) parseExecute(stmt *sql.Stmt, operType string, vals []interface{}) (int64, error) {
defer stmt.Close()
var rowsAffected int64
var err error
result, errs := stmt.Exec(vals...)
if errs != nil {
    return 0, errs
}

switch operType {
case "insert":
    // get rows affected
    rowsAffected, err = result.RowsAffected()
    dba.RowsAffected = int(rowsAffected)
    // get last insert id
    rowsAffected, err = result.LastInsertId()
    dba.LastInsertId = int(rowsAffected)
case "update":
    rowsAffected, err = result.RowsAffected()
case "delete":
    rowsAffected, err = result.RowsAffected()
}

return rowsAffected, err
}

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