Question

我需要将xml发送到商店程序。 xml看起来像

<NewDataSet>  
<param>  
<SearchField>EmployeeID</SearchField>  
<FilterCondition> >= </FilterCondition>  
<ConditionData>201</ConditionData>  
<MatchCase>0</MatchCase>  
</params>
<param>    
<SearchField>DeptID</SearchField>  
<FilterCondition> = </FilterCondition>  
<ConditionData>AC01</ConditionData>  
<MatchCase>0</MatchCase>  
</params>  
<param>    
<SearchField>Dob</SearchField>  
<FilterCondition> <= </FilterCondition>  
<ConditionData>23-MAR-2010</ConditionData>  
<MatchCase>0</MatchCase>  
</params>  
</NewDataSet>

SearchField标记包含将在其上进行搜索的搜索字段名称
FilterCondition标记将保留我用来搜索和比较的运算符，例如'％''＆lt; =''＆lt; ='etc
ConditionData标签将是我们将搜索的实际值
MatchCase表示它区分大小写

我可以加载xml并迭代while循环游标并生成where子句。我的问题是如何根据字段数据类型生成where子句。

如果字段是字符串，那么我们总是在''单引号中进行比较如果字段是数字或位类型，那么我们可以比较没有单引号如果该字段是日期时间，那么我想比较喜欢 convert(@dob,varchar,112) > '20100101'

所以我的问题是如何基于数据类型生成where子句。我需要动态获取字段数据类型，并相应地构建where子句。请分享最好的主意。感谢

我改变了我的xml位。我为每个字段都包含表名。所以请告诉我在这个sql中需要更改的内容，以显示每个字段的数据类型。显示我需要加入系统表的数据类型。所以请在你的sql中进行必要的更改，以便与sys table一起加入fetch＆amp;显示每个字段的数据类型。

INSERT INTO @tbl_WhereClause (SearchField, Operator, ConditionData,   MatchCase,TableName)
SELECT  A.B.value('(SearchField)[1]', 'VARCHAR(255)' ) SearchField, 
    A.B.value('(FilterCondition)[1]', 'VARCHAR(25)' ) Operator, 
    A.B.value('(ConditionData)[1]', 'VARCHAR(MAX)' ) ConditionData,
    A.B.value('(MatchCase)[1]', 'BIT' ) MatchCase,
    A.B.value('(Table)[1]', 'VARCHAR(MAX)' ) TableName
FROM    @WhereClause_XML.nodes('/NewDataSet/param') A(B)

这是我的解决方案。

/*
XML DATA SAMPLE
<NewDataSet>
<param>
    <SearchField>EmpID</SearchField>
    <FilterCondition> >= </FilterCondition>
    <ConditionData>201</ConditionData>
    <MatchCase>0</MatchCase>
    <Table>Employee</Table>
</param>
<param>  
    <SearchField>DeptName</SearchField>
    <FilterCondition> = </FilterCondition>
    <ConditionData>AC01</ConditionData>
    <MatchCase>1</MatchCase>
    <Table>Department</Table>
</param>
<param>  
    <SearchField>Dob</SearchField>
    <FilterCondition> >= </FilterCondition>
    <ConditionData>20120104</ConditionData>
    <MatchCase>0</MatchCase>
    <Table>Employee</Table>
</param>
  </NewDataSet>'
  */

  CREATE PROCEDURE GenericSearch
  (
@WhereClause_XML XML,
@LogicalOperator VARCHAR(3)
  )
  AS

 BEGIN

 DECLARE @SearchField VARCHAR(255),
 @Operator VARCHAR(25),
 @ConditionData VARCHAR(MAX),
 @MatchCase BIT,
 @TableName VARCHAR(MAX),
 @Validity VARCHAR(100),
 @ColumnType VARCHAR(128),
 @ColumnPrecision INT,
 @ColumnScale INT,
 @ColumnNullable bit,
 @WhereClause VARCHAR(MAX)

 DECLARE @tbl_WhereClause AS TABLE 
 (
SearchField VARCHAR(255),
Operator VARCHAR(25),
ConditionData VARCHAR(MAX),
MatchCase BIT,
TableName VARCHAR(MAX),
Validity VARCHAR(100),
ColumnType VARCHAR(128),
ColumnPrecision INT,
ColumnScale INT,
ColumnNullable bit
 )


 INSERT INTO @tbl_WhereClause (SearchField, Operator, ConditionData,   MatchCase,TableName, 
 Validity, ColumnType, ColumnPrecision, ColumnScale, ColumnNullable)

SELECT  A.B.value('(SearchField)[1]', 'VARCHAR(255)' ) SearchField,
A.B.value('(FilterCondition)[1]', 'VARCHAR(25)' ) Operator,
A.B.value('(ConditionData)[1]', 'VARCHAR(MAX)' ) ConditionData,
A.B.value('(MatchCase)[1]', 'BIT' ) MatchCase,
A.B.value('(Table)[1]', 'VARCHAR(MAX)' ) TableName,
CASE WHEN t.NAME+c.NAME IS NULL THEN 'invalid' ELSE 'valid' END ,
ty.NAME,
c.PRECISION,
c.Scale,
c.Is_Nullable
FROM    @WhereClause_XML.nodes('/NewDataSet/param') A(B)
LEFT JOIN sys.tables t ON t.name = A.B.value('(Table)[1]', 'VARCHAR(MAX)' )
LEFT JOIN sys.COLUMNS c ON T.OBJECT_ID = c.OBJECT_ID AND c.name =     A.B.value('(SearchField)[1]', 'VARCHAR(255)' )
LEFT JOIN sys.types ty ON c.system_type_id = ty.system_type_id 

--SELECT * FROM @tbl_WhereClause

SET @WhereClause= 'WHERE 1=1'
DECLARE SearchCursor CURSOR FOR 
SELECT * FROM @tbl_WhereClause

OPEN SearchCursor

FETCH NEXT FROM SearchCursor 
INTO @SearchField,  @Operator,@ConditionData,@MatchCase,@TableName,@Validity,@ColumnType,@ColumnPrecision,@Colu    mnScale,@ColumnNullable

WHILE @@FETCH_STATUS = 0
BEGIN

IF CHARINDEX('INT', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) +  @SearchField + space(1)+@Operator+space(1)+@ConditionData
END
ELSE IF CHARINDEX('NUMERIC', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) + @SearchField + space(1)+@Operator+space(1)+@ConditionData
END
ELSE IF CHARINDEX('BIT', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) + @SearchField + space(1)+@Operator+space(1)+@ConditionData
END
ELSE IF CHARINDEX('DECIMAL', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) + @SearchField + space(1)+@Operator+space(1)+@ConditionData
END
ELSE IF CHARINDEX('FLOAT', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) + @SearchField + space(1)+@Operator+space(1)+@ConditionData
END
ELSE IF CHARINDEX('REAL', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) + @SearchField + space(1)+@Operator+space(1)+@ConditionData
END
ELSE IF CHARINDEX('MONEY', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) + @SearchField + space(1)+@Operator+space(1)+@ConditionData
END
ELSE IF CHARINDEX('DATE', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) + 'CONVERT(varchar,'+@SearchField+',112)' +  space(1)+@Operator+'CONVERT(varchar,'''+@ConditionData+''',112)'
END
ELSE IF CHARINDEX('CHAR', UPPER(@ColumnType)) > 0 
BEGIN
    SET @WhereClause = @WhereClause + space(1)+ @LogicalOperator + space(1) + @SearchField + space(1)+@Operator+''''+@ConditionData+''''
END 

FETCH NEXT FROM SearchCursor 
INTO @SearchField,  @Operator,@ConditionData,@MatchCase,@TableName,@Validity,@ColumnType,@ColumnPrecision,@ColumnScale,@ColumnNullable
    END

    CLOSE SearchCursor  
    DEALLOCATE SearchCursor 

    SELECT @WhereClause
    END

Answer 1

2个小东西，1＆lt; ＆安培; ＆GT;在XML标记中是非常非法的，如果你想要可靠地解析它，生成XML需要将这些编码到approriate实体引用：

&lt;    <    less than
&gt;    >    greater than
&amp;   &    ampersand
&apos;  '    apostrophe
&quot;  "    quotation mark

此外，您的结束节点和开放节点有一个拼写错误，例如＆lt; param＆gt;被＆lt; params＆gt;关闭（注意'S'） - 假设这是一个错字。

尽管如此，最难的部分是将XML解析为可用于构建动态SQL的有用数据。您可以通过将XML解析为表来执行此操作：

DECLARE @tbl_WhereClause AS TABLE (
    SearchField VARCHAR(255),
    Operator VARCHAR(25),
    ConditionData VARCHAR(MAX),
    MatchCase BIT
)

DECLARE @WhereClause_XML XML 
SET @WhereClause_XML = '
<NewDataSet>   
<param>   
<SearchField>EmployeeID</SearchField>   
<FilterCondition> &gt;= </FilterCondition>   
<ConditionData>201</ConditionData>   
<MatchCase>0</MatchCase>   
</param> 
<param>     
<SearchField>DeptID</SearchField>   
<FilterCondition> = </FilterCondition>   
<ConditionData>AC01</ConditionData>   
<MatchCase>0</MatchCase>   
</param>   
<param>     
<SearchField>Dob</SearchField>   
<FilterCondition> &lt;= </FilterCondition>   
<ConditionData>23-MAR-2010</ConditionData>   
<MatchCase>0</MatchCase>   
</param>   
</NewDataSet>'

INSERT INTO @tbl_WhereClause (SearchField, Operator, ConditionData, MatchCase)
SELECT  A.B.value('(SearchField)[1]', 'VARCHAR(255)' ) SearchField, 
        A.B.value('(FilterCondition)[1]', 'VARCHAR(25)' ) Operator, 
        A.B.value('(ConditionData)[1]', 'VARCHAR(MAX)' ) ConditionData,
        A.B.value('(MatchCase)[1]', 'BIT' ) ConditionData
FROM    @WhereClause_XML.nodes('/NewDataSet/param') A(B) 

SELECT * FROM @tbl_WhereClause

一旦你获得了解析数据，它只是一个简单的案例（如果不是单调乏味）迭代表格并构建where clase字符串 - 如果你需要这方面的帮助，请告诉我。

从xml生成动态where子句

1 个答案: