Question

使用此命令时出现此错误

MySqlCommand cmdDataBase = new MySqlCommand("select * from employee.transaction where department = '" + this.department.Text + "', month = '" + this.dateTimePicker1.Value.Month.ToString() + "' and year = '" + this.dateTimePicker1.Value.Year.ToString() + "' ;", conDataBase);

错误： - 您的sql语法中有错误;请查看与您的mysql服务器版本对应的手册，以获得正确的语法，以便在＆＃39;附近使用。月份=＆＃39; 7＆＃39;和年=＆＃39; 2015＆＃34;在第1行

月份和年份在我的mysql版本（版本5.6.25）中是Int类型的

有人可以帮忙吗？

Answer 1

您不能在WHERE子句中的过滤器之间使用逗号。

我认为您尝试写为AND month...而不是, month...

但更重要的是，您应该始终使用parameterized queries.此类字符串连接可用于SQL Injection次攻击。

using(var conDataBase = MySqlConnection(conString))
using(var cmdDataBase = conDataBase.CreateCommand())
{
   cmdDatabase.CommandText = @"select * from employee.transaction 
                               where department = @department AND month = @month AND year = @year";
   cmdDatabase.Parameters.AddWithValue("@department", this.department.Text);
   cmdDatabase.Parameters.AddWithValue("@month", this.dateTimePicker1.Value.Month.ToString());
   cmdDatabase.Parameters.AddWithValue("@year", this.dateTimePicker1.Value.Year.ToString());
   // Do your work here
}

同样基于您的列名，我强烈怀疑您的month和year列应为数字类型，而不是字符类型。

Answer 2

试试这个， MySqlCommand cmdDataBase = new MySqlCommand（“select * from employee.transaction where department ='”+ this.department.Text +“'and month ='”+ this.dateTimePicker1.Value.Month.ToString（）+“'and year = '“+ this.dateTimePicker1.Value.Year.ToString（）+”'“，conDataBase）;

使用select查询时出现mysql语法错误

2 个答案: