mysql数据库字段中 判断字段中字符类型 问题

您如果想要判断类型的话，可以进行转换 比如

select to_char(name) from table_name; ---这样就把您想要的数据NAME列转换为字符型;

select to_num(name) from table_name; ---这样就把您想要的数据NAME列转换为数字型;

您所说的自动判断 貌似没有

'添加一个按钮，然后粘贴如下代码，点按钮就可以看结果，算法比较复杂，不明白的百度HI我

Private Function op(ByVal x As Double, o As Integer, ByVal y As Double) As Double

Select Case o

Case 0

op = x + y

Case 1

op = x - y

Case 2

op = x y

Case 3

If y <> 0 Then

op = x / y

End If

End Select

End Function

Private Function transchar(o As Integer) As String

Select Case o

Case 0

transchar = "+"

Case 1

transchar = "-"

Case 2

transchar = ""

Case 3

transchar = "/"

End Select

End Function

Private Function Cal1(a As Integer, i As Integer, b As Integer, j As Integer, c As Integer, k As Integer, d As Integer) As Double

Cal1 = op(a, i, b)

Cal1 = op(Cal1, j, c)

Cal1 = op(Cal1, k, d)

End Function

Private Function Cal2(a As Integer, i As Integer, b As Integer, j As Integer, c As Integer, k As Integer, d As Integer) As Double

Cal2 = op(b, j, c)

Cal2 = op(a, i, Cal2)

Cal2 = op(Cal2, k, d)

End Function

Private Function Cal3(a As Integer, i As Integer, b As Integer, j As Integer, c As Integer, k As Integer, d As Integer) As Double

Dim rz1 As Double

Cal3 = op(a, i, b)

rz1 = op(c, k, d)

Cal3 = op(Cal3, j, rz1)

End Function

Private Function Cal4(a As Integer, i As Integer, b As Integer, j As Integer, c As Integer, k As Integer, d As Integer) As Double

Cal4 = op(b, j, c)

Cal4 = op(Cal4, k, d)

Cal4 = op(a, i, Cal4)

End Function

Private Function Cal5(a As Integer, i As Integer, b As Integer, j As Integer, c As Integer, k As Integer, d As Integer) As Double

Cal5 = op(c, k, d)

Cal5 = op(b, j, Cal5)

Cal5 = op(a, i, Cal5)

End Function

Private Function calc(a() As Integer) As Boolean

Dim i As Integer, j As Integer, k As Integer

Dim b As Boolean

For i = 0 To 3

For j = 0 To 3

For k = 0 To 3

If Cal1(a(0), i, a(1), j, a(2), k, a(3)) = 24 Then

Print "(("; a(0); transchar(i); a(1); ")"; transchar(j); a(2); ")"; transchar(k); a(3); "= 24"

End If

If Not (i = j And j = k And (i Mod 2) = 0) Then

If (Not (i = j And (i Mod 2) = 0)) Or ((i Mod 2) = 0 And j = i + 1) Then

If Cal2(a(0), i, a(1), j, a(2), k, a(3)) = 24 Then

Print "("; a(0); transchar(i); "("; a(1); transchar(j); a(2); "))"; transchar(k); a(3); "= 24"

b = True

End If

End If

If Cal3(a(0), i, a(1), j, a(2), k, a(3)) = 24 Then

Print "("; a(0); transchar(i); a(1); ")"; transchar(j); "("; a(2); transchar(k); a(3); ")"; "= 24"

b = True

End If

If Cal4(a(0), i, a(1), j, a(2), k, a(3)) = 24 Then

Print a(0); transchar(i); "(("; a(1); transchar(j); a(2); ")"; transchar(k); a(3); ")"; "= 24"

b = True

End If

If (Not ((j = k And (j Mod 2) = 0) Or ((j Mod 2) = 0 And k = j + 1))) Then

If Cal5(a(0), i, a(1), j, a(2), k, a(3)) = 24 Then

Print a(0); transchar(i); "("; a(1); transchar(j); "("; a(2); transchar(k); a(3); "))"; "= 24"

b = True

End If

End If

End If

Next k

Next j

Next i

calc = b

End Function

Private Sub Command1_Click()

Dim a(0 To 3) As Integer

Dim b(0 To 3) As Integer

Dim i As Integer

Randomize Timer

MeCls

Print "4个随机数是:";

For i = 0 To 3

a(i) = Int(Rnd() 13 + 1)

Print a(i); " ";

Next i

Print

Print "计算结果"

If calc(a) = False Then

Print "无解"

End If

End Sub

这个问题是典型的设标志的问题，对已用过的数值设标志，就能根据标志知道哪些数值没有使用过。设标志的方法很多，如果数值的范围不大，效率最高的就是用用数组（字符串也是数组），你的问题就是这种情况。给个简单的例子给你，具体算法自己看看代码吧。例子中把未使用过的数值放到下拉列表框中，这样应该更方便后续处理。如果你确实要放到文本框中，有了算法你自己不难做到。

代码如下：

<php

$sql="select from checklist where game_id=$gid and task='$task' and status='$status'";

$result=mysql_query($sql);

$row = mysql_fetch_array($result, MYSQL_ASSOC);

  if (!mysql_num_rows($result))

      {

          echo "record doesn't exist~~~~~!!!!!!";

      }

  else

      {             // echo mysql_num_rows($result)"\n";

          echo $row['game_id'];

          echo $row['task'];

      }

>

扩展资料

访问MySql一般步骤

1）连接MySql服务器

使用mysql_connect()函数建立与MySql服务器的连接。

2）选择MySql数据库

使用mysql_select_db()函数选择MySql服务器上的数据库，并与数据库建立连接。

3）执行SQL语句

使用mysql_query()函数执行SQL语句。（包括增加、删除、修改、查询、显示）

4）关闭结果集

使用mysql_free_result($result)关闭结果集，以释放资源。

当然先判断是否存在才取值， 有值还需要判断存在吗？

if(RequestQueryString[ "id" ]!=null&&RequestQueryString[ "id" ]!="")

{

}

1身份z号码生成是有规则的，利用此规则在程序端就可以控制的；

2若是查证一个身份z号码是否在数据库中，直接创建一个唯一索引，然后SELECT查询即可；

3身份z是有规则的，可以判断头部是否符合库能查到，以及中间8位数字是否符合年月日的规则，身份z的字符个数。

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