代码1
[WebMethod]
public DataSet DataVisit(string strClassID)
{
string mySelectQuery="Select StudentID,StudentName,StudentRe from StudentInfo where ClassID='"+strClassID+"'";
string strConn="user id =sa;password=;server=SSE-CAT;database=Info";
SqlConnection myConnection=new SqlConnection(strConn);
SqlCommand myCommand=new SqlCommand (mySelectQuery,myConnection);
myConnection.Open();
SqlDataAdapter Adapter=new SqlDataAdapter();
Adapter.SelectCommand=myCommand;
DataSet myDs=new DataSet();
Adapter.Fill(myDs,"Student");
myConnection.Close();
return myDs;
}
注意第五行的ClassID='"+strClassID+"'; 代码2
[WebMethod]
public DataSet DataVisit(string strClassID)
{
string mySelectQuery="Select StudentID,StudentName,StudentRe from StudentInfo where ClassID='strClassID'";
string strConn="user id =sa;password=;server=SSE-CAT;database=Info";
SqlConnection myConnection=new SqlConnection(strConn);
SqlCommand myCommand=new SqlCommand (mySelectQuery,myConnection);
myConnection.Open();
SqlDataAdapter Adapter=new SqlDataAdapter();
Adapter.SelectCommand=myCommand;
DataSet myDs=new DataSet();
Adapter.Fill(myDs,"Student");
myConnection.Close();
return myDs;
}
注意这里是 ClassID='strClassID'
两段代码就是这个地方不同代码1产生的xml文件
<?xml version="1.0" encoding="utf-8" ?>
- <DataSet xmlns="http://tempuri.org/">
- <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
- <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:Locale="zh-CN">
- <xs:complexType>
- <xs:choice maxOccurs="unbounded">
- <xs:element name="Student">
- <xs:complexType>
- <xs:sequence>
<xs:element name="StudentID" type="xs:string" minOccurs="0" />
<xs:element name="StudentName" type="xs:string" minOccurs="0" />
<xs:element name="StudentRe" type="xs:int" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
- <diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">
- <NewDataSet xmlns="">
- <Student diffgr:id="Student1" msdata:rowOrder="0">
<StudentID>99055000</StudentID>
<StudentName>李明</StudentName>
<StudentRe>90</StudentRe>
</Student>
- <Student diffgr:id="Student2" msdata:rowOrder="1">
<StudentID>99055001</StudentID>
<StudentName>王秒</StudentName>
<StudentRe>88</StudentRe>
</Student>
- <Student diffgr:id="Student3" msdata:rowOrder="2">
<StudentID>99055003</StudentID>
<StudentName>王丽丽</StudentName>
<StudentRe>77</StudentRe>
</Student>
</NewDataSet>
</diffgr:diffgram>
</DataSet> 代码2产生的xml
<?xml version="1.0" encoding="utf-8" ?>
- <DataSet xmlns="http://tempuri.org/">
- <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
- <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:Locale="zh-CN">
- <xs:complexType>
- <xs:choice maxOccurs="unbounded">
- <xs:element name="Student">
- <xs:complexType>
- <xs:sequence>
<xs:element name="StudentID" type="xs:string" minOccurs="0" />
<xs:element name="StudentName" type="xs:string" minOccurs="0" />
<xs:element name="StudentRe" type="xs:int" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1" />
</DataSet>
代码1的xml文件列出了student表里的各个列,而代码2则没有,两段代码只是相差一对引号,为什么会产生这种情况,我是asp.net的初学者,请各位大虾们指教
[WebMethod]
public DataSet DataVisit(string strClassID)
{
string mySelectQuery="Select StudentID,StudentName,StudentRe from StudentInfo where ClassID='"+strClassID+"'";
string strConn="user id =sa;password=;server=SSE-CAT;database=Info";
SqlConnection myConnection=new SqlConnection(strConn);
SqlCommand myCommand=new SqlCommand (mySelectQuery,myConnection);
myConnection.Open();
SqlDataAdapter Adapter=new SqlDataAdapter();
Adapter.SelectCommand=myCommand;
DataSet myDs=new DataSet();
Adapter.Fill(myDs,"Student");
myConnection.Close();
return myDs;
}
注意第五行的ClassID='"+strClassID+"'; 代码2
[WebMethod]
public DataSet DataVisit(string strClassID)
{
string mySelectQuery="Select StudentID,StudentName,StudentRe from StudentInfo where ClassID='strClassID'";
string strConn="user id =sa;password=;server=SSE-CAT;database=Info";
SqlConnection myConnection=new SqlConnection(strConn);
SqlCommand myCommand=new SqlCommand (mySelectQuery,myConnection);
myConnection.Open();
SqlDataAdapter Adapter=new SqlDataAdapter();
Adapter.SelectCommand=myCommand;
DataSet myDs=new DataSet();
Adapter.Fill(myDs,"Student");
myConnection.Close();
return myDs;
}
注意这里是 ClassID='strClassID'
两段代码就是这个地方不同代码1产生的xml文件
<?xml version="1.0" encoding="utf-8" ?>
- <DataSet xmlns="http://tempuri.org/">
- <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
- <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:Locale="zh-CN">
- <xs:complexType>
- <xs:choice maxOccurs="unbounded">
- <xs:element name="Student">
- <xs:complexType>
- <xs:sequence>
<xs:element name="StudentID" type="xs:string" minOccurs="0" />
<xs:element name="StudentName" type="xs:string" minOccurs="0" />
<xs:element name="StudentRe" type="xs:int" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
- <diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">
- <NewDataSet xmlns="">
- <Student diffgr:id="Student1" msdata:rowOrder="0">
<StudentID>99055000</StudentID>
<StudentName>李明</StudentName>
<StudentRe>90</StudentRe>
</Student>
- <Student diffgr:id="Student2" msdata:rowOrder="1">
<StudentID>99055001</StudentID>
<StudentName>王秒</StudentName>
<StudentRe>88</StudentRe>
</Student>
- <Student diffgr:id="Student3" msdata:rowOrder="2">
<StudentID>99055003</StudentID>
<StudentName>王丽丽</StudentName>
<StudentRe>77</StudentRe>
</Student>
</NewDataSet>
</diffgr:diffgram>
</DataSet> 代码2产生的xml
<?xml version="1.0" encoding="utf-8" ?>
- <DataSet xmlns="http://tempuri.org/">
- <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
- <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:Locale="zh-CN">
- <xs:complexType>
- <xs:choice maxOccurs="unbounded">
- <xs:element name="Student">
- <xs:complexType>
- <xs:sequence>
<xs:element name="StudentID" type="xs:string" minOccurs="0" />
<xs:element name="StudentName" type="xs:string" minOccurs="0" />
<xs:element name="StudentRe" type="xs:int" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1" />
</DataSet>
代码1的xml文件列出了student表里的各个列,而代码2则没有,两段代码只是相差一对引号,为什么会产生这种情况,我是asp.net的初学者,请各位大虾们指教
ClassID='"+strClassID+"'"; 也就是sql语句是否返回了数据
ClassID="+strClassID+"";
字符型的这样写
ClassID='"+strClassID+"'";