📄 sql相关.txt
字号:
FROM table_name
WHERE column1 = ***
[AND column2 > yyy] [OR column3 <> zzz]
说明:
1.'*'表示全部的栏位都列出来
2.WHERE 之後是接条件式,把符合条件的资料列出来
SELECT column1,column2
FROM table_name
ORDER BY column2 [DESC]
说明:
ORDER BY 是指定以某个栏位做排序,[DESC]是指从大到小排列,若
没有指明,则是从小到大排列
组合查询
组合查询是指所查询得资料来源并不只有单一的表格,而是联合一个以上的表格才能够得到结果的。
SELECT *
FROM table1,table2
WHERE table1.colum1=table2.column1
说明:
1.查询两个表格中其中 column1 值相同的资料
2.当然两个表格相互比较的栏位,其资料形态必须相同
3.一个复杂的查询其动用到的表格可能会很多个
整合性的查询:
SELECT COUNT (*)
FROM table_name
WHERE column_name = ***
说明:
查询符合条件的资料共有几笔
SELECT SUM(column1)
FROM table_name
说明:
1.计算出总和,所选的栏位必须是可数的数字形态
2.除此以外还有 AVG() 是计算平均、MAX()、MIN()
计算最大最小值的整合性查询
SELECT column1,AVG(column2)
FROM table_name
GROUP BY column1
HAVING AVG(column2) > ***
说明:
1.GROUP BY: 以column1 为一组计算 column2 的平均值
必须和 AVG、SUM 等整合性查询的关键字一起使用
2.HAVING : 必须和 GROUP BY 一起使用作为整合性的限制
复合性的查询
SELECT *
FROM table_name1
WHERE EXISTS (
SELECT *
FROM table_name2
WHERE conditions )
说明:
1.WHERE 的 conditions 可以是另外一个的 query
2.EXISTS 在此是指存在与否
SELECT *
FROM table_name1
WHERE column1 IN (
SELECT column1
FROM table_name2
WHERE conditions )
说明
1. IN 後面接的是一个集合,表示column1 存在集合里面
2. SELECT 出来的资料形态必须符合 column1
其他查询
SELECT *
FROM table_name1
WHERE column1 LIKE 'x%'
说明:
1.LIKE 必须和後面的'x%' 相呼应表示以 x为开头的字串
SELECT *
FROM table_name1
WHERE column1 IN ('***','yyy',..)
说明
1. IN 後面接的是一个集合,表示column1 存在集合里面
SELECT *
FROM table_name1
WHERE column1 BETWEEN xx AND yy
说明
1. BETWEEN 表示 column1 的值介於 xx 和 yy 之间
更改资料:
UPDATE table_name
SET column1='***'
WHERE conditoins
说明:
1.更改某个栏位设定其值为'***'
2.conditions 是所要符合的条件、若没有 WHERE 则
整个 table 的那个栏位都会全部被更改
删除资料:
DELETE FROM table_name
WHERE conditions
说明:删除符合条件的资料
ACCESS中增加和修改字段属性语句
增加表中字段:
alter table tablename add id int IDENTITY (1, 1) NOT NULL 'ID自动编者编号
alter table tablename add 字段名 bit '是与否
alter table tablename add 字段名 varchar(250) '文本长度250
alter table tablename add 字段名 int default 0 '长整默认0
alter table tablename add 字段名text '备注
alter table tablename add 字段名 datetime default Now() '时间默认now()
alter table tablename add 字段名 image '图象
alter table tablename add 字段名 money '货币
修改表中字段
alter table tablename alter column id int IDENTITY (1, 1) NOT NULL '修改为ID自动编者编号
alter table tablename alter column columnname bit '修改为是与否
alter table tablename alter column columnname varchar(250) '修改为文本长度250
alter table tablename alter column columnname int default 0 '修改为长整默认0
alter table tablename alter column columnname text '修改为备注
alter table tablename alter column columnname datetime default Now() '修改为时间默认now()
alter table tablename alter column columnname image '修改为图象
alter table tablename alter column columnname money '修改为货币
topmargin=0
如何实现网页的向前向后,如history.go(0)等的有关内容
向前history.back(-1)或history.go(-1)
<%
If ......then
%>
<script language="vbscript">
history.back(-1)
</script>
<%
end if
%>
ALTER TABLE 表名 DROP COLUMN 字段名
数据库查询中的特殊字符的问题 -- 思路[转帖]
在进行数据库的查询时,会经常遇到这样的情况:
例如想在一个用户数据库中查询他的用户名和他的密码,但恰好该用户使用的名字和密码中有特殊的字符,例如单引号,“|”号,双引号或者连字符“&”。
例如他的名字是1"test,密码是A|&900
这时当你执行以下的查询语句时,肯定会报错:
SQL = "SELECT * FROM SecurityLevel WHERE UID="" & UserID & """
SQL = SQL & " AND PWD="" & Password & """
因为你的SQL将会是这样:
SELECT * FROM SecurityLevel WHERE UID="1"test" AND PWD="A|&900"
在SQL中,"|"为分割字段用的,显然会出错了。现在提供下面的几个函数 专门用来处理这些头疼的东西:
Function ReplaceStr (TextIn, ByVal SearchStr As String, _
ByVal Replacement As String, _
ByVal CompMode As Integer)
Dim WorkText As String, Pointer As Integer
If IsNull(TextIn) Then
ReplaceStr = Null
Else
WorkText = TextIn
Pointer = InStr(1, WorkText, SearchStr, CompMode)
Do While Pointer > 0
WorkText = Left(WorkText, Pointer - 1) & Replacement & _
Mid(WorkText, Pointer + Len(SearchStr))
Pointer = InStr(Pointer + Len(Replacement), WorkText, SearchStr, CompMode)
Loop
ReplaceStr = WorkText
End If
End Function
Function SQLFixup(TextIn)
SQLFixup = ReplaceStr(TextIn, """, """", 0)
End Function
Function JetSQLFixup(TextIn)
Dim Temp
Temp = ReplaceStr(TextIn, """, """", 0)
JetSQLFixup = ReplaceStr(Temp, "|", "" & chr(124) & "", 0)
End Function
Function FindFirstFixup(TextIn)
Dim Temp
Temp = ReplaceStr(TextIn, """, "" & chr(39) & "", 0)
FindFirstFixup = ReplaceStr(Temp, "|", "" & chr(124) & "", 0)
End Function
有了上面几个函数后,当你在执行一个sql前,请先使用
SQL = "SELECT * FROM SecurityLevel WHERE UID="" & SQLFixup(UserID) & """
SQL = SQL & " AND PWD="" & SQLFixup(Password) & """
列出数据库中的所有表------吐血推荐
<%
strConn="DBQ="+server.mappath("kendylan.mdb")+";DefaultDir=;DRIVER={Microsoft Access Driver (*.mdb)};"
set objConn=server.createobject("Adodb.connection")
objConn.open strConn
set rsSchema=objConn.openSchema(20)
rsSchema.movefirst
Do Until rsSchema.EOF
if rsSchema("TABLE_TYPE")="TABLE" then
response.write rsSchema("TABLE_NAME") & "<br>"
end if
rsSchema.movenext
Loop
set objConn=nothing
%>
以前这里就有说过啊
[转帖]万能数据库连接程序!
万能数据库连接程序!
作者: 阿泰 点击链接查看作者详细信息
简介: 连接各种类型数据库 及 对数据库操作的函数
下面这部分程序可说是万能的数据库连接程序几乎可以连接所有的MS数据库,自己拿去研究吧(这个程序是“ASP网页制作教程”这本书里面的——一本好书):
<%
'---------------------------------------------------
Function GetMdbConnection( FileName )
Dim Provider, DBPath
Provider = "Provider=Microsoft.Jet.OLEDB.4.0;"
DBPath = "Data Source=" & Server.MapPath(FileName)
Set GetMdbConnection = GetConnection( Provider & DBPath )
End Function
'---------------------------------------------------
Function GetSecuredMdbConnection( FileName, Password )
Dim Provider, DBPath
Provider = "Provider=Microsoft.Jet.OLEDB.4.0;"
DBPath = "Data Source=" & Server.MapPath(FileName)
Set GetSecuredMdbConnection = GetConnection( Provider & DBPath & ";Jet OLEDB:Database Password=" & Password ) End Function
'---------------------------------------------------
Function GetDbcConnection( FileName )
Dim Driver, SourceType, DBPath
Driver = "Driver={Microsoft Visual FoxPro Driver};"
SourceType = "SourceType=DBC;"
DBPath = "SourceDB=" & Server.MapPath( FileName )
Set GetDbcConnection = GetConnection( Driver & SourceType & DBPath )
End Function
'---------------------------------------------------
Function GetDbfConnection( Directory )
Dim Driver, SourceType, DBPath
Driver = "Driver={Microsoft Visual FoxPro Driver};"
SourceType = "SourceType=DBF;"
DBPath = "SourceDB=" & Server.MapPath( Directory )
Set GetDbfConnection = GetConnection( Driver & SourceType & DBPath )
End Function
'---------------------------------------------------
Function GetExcelConnection( FileName )
Dim Driver, DBPath
Driver = "Driver={Microsoft Excel Driver (*.xls)};"
DBPath = "DBQ=" & Server.MapPath( FileName )
Set GetExcelConnection = GetConnection( Driver & "ReadOnly=0;" & DBPath ) End Function
'---------------------------------------------------
Function GetTextConnection( Directory )
Dim Driver, DBPath
Driver = "Driver={Microsoft Text Driver (*.txt; *.csv)};"
DBPath = "DBQ=" & Server.MapPath( Directory )
Set GetTextConnection = GetConnection( Driver & DBPath )
End Function
'---------------------------------------------------
Function GetSQLServerConnection( Computer, UserID, Password, Db )
Dim Params, conn
Set GetSQLServerConnection = Nothing
Params = "Provider=SQLOLEDB.1"
Params = Params & ";Data Source=" & Computer
Params = Params & ";User ID=" & UserID
Params = Params & ";Password=" & Password
Params = Params & ";Initial Catalog=" & Db
Set conn = Server.CreateObject("ADODB.Connection")
conn.Open Params
Set GetSQLServerConnection = conn
End Function
'---------------------------------------------------
Function GetMdbRecordset( FileName, Source )
Set GetMdbRecordset = GetMdbRs( FileName, Source, 2, "" )
End Function
'---------------------------------------------------
Function GetMdbStaticRecordset( FileName, Source )
Set GetMdbStaticRecordset = GetMdbRs( FileName, Source, 3, "" )
End Function
'---------------------------------------------------
Function GetSecuredMdbRecordset( FileName, Source, Password )
Set GetSecuredMdbRecordset = GetMdbRs( FileName, Source, 2, Password ) End Function
'---------------------------------------------------
Function GetSecuredMdbStaticRecordset( FileName, Source, Password )
Set GetSecuredMdbStaticRecordset = GetMdbRs( FileName, Source, 3, Password ) End Function
'---------------------------------------------------
Function GetDbfRecordset( Directory, SQL )
Set GetDbfRecordset = GetOtherRs( "Dbf", Directory, SQL, 2 )
End Function
'---------------------------------------------------
Function GetDbfStaticRecordset( Directory, SQL )
Set GetDbfStaticRecordset = GetOtherRs( "Dbf", Directory, SQL, 3 )
End Function
'---------------------------------------------------
Function GetDbcRecordset( FileName, SQL )
Set GetDbcRecordset = GetOtherRs( "Dbc", FileName, SQL, 2 )
End Function
'---------------------------------------------------
Function GetDbcStaticRecordset( FileName, SQL )
Set GetDbcStaticRecordset = GetOtherRs( "Dbc", FileName, SQL, 3 )
End Function
'---------------------------------------------------
Function GetExcelRecordset( FileName, SQL )
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