SQL查询中使用的表的列表

Question

有没有办法获取SQL查询中使用的表列表？示例:我有类似的东西:

SELECT * FROM Table t JOIN OtherTable ON t.id=OtherTable.t_id

我希望得到

Table, OtherTable

谢谢

Answer 1

您可以在查询后立即使用此sql脚本.它将返回上次执行的查询中使用的表列表:

   SELECT Field1, Field2 
   FROM Table t JOIN OtherTable ON t.id=OtherTable.t_id

  ;WITH vwQueryStats AS(
     SELECT 
      COALESCE(OBJECT_NAME(s2.objectid),'Ad-Hoc') AS ProcName
      ,execution_count
      ,s2.objectid
      ,(
         SELECT TOP 1 
            SUBSTRING(s2.TEXT,statement_start_offset / 2+1 
            ,( ( CASE WHEN statement_end_offset = -1
                THEN (LEN(CONVERT(NVARCHAR(MAX),s2.TEXT)) * 2)
                ELSE statement_end_offset END)- statement_start_offset) / 2+1)) AS sql_statement
            ,last_execution_time
         FROM sys.dm_exec_query_stats AS s1
         CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS s2
    )
    SELECT TOP 1 * 
    INTO #lastQueryStats
    FROM vwQueryStats x
    WHERE sql_statement NOT like 'WITH vwQueryStats AS%'
    ORDER BY last_execution_time DESC

    SELECT
    TABLE_NAME
    FROM #lastQueryStats, INFORMATION_SCHEMA.TABLES tab 
    WHERE CHARINDEX( tab.TABLE_NAME, sql_statement) > 0


    DROP TABLE #lastQueryStats 

我已经从这篇文章中获取了检索最后执行的查询的查询,并对其进行了一些修改以与您的示例相匹配.

输出将按您的要求输出:

 Table
 OtherTable

然后,如果你想让它们以逗号分隔,你可以这样做:

DECLARE @tableNames VARCHAR(MAX) 

SELECT @tableNames = COALESCE(@tableNames + ', ', '') + TABLE_NAME
FROM   #lastQueryStats, INFORMATION_SCHEMA.TABLES tab 
WHERE  CHARINDEX( tab.TABLE_NAME, sql_statement) > 0

SELECT @tableNames 

但是,您应该警惕在"通常"生产或QA环境中同时执行数千个查询时,这可能不起作用,因为在您的第一个查询和从db stats中提取信息的查询之间可以执行另一个查询.

希望能帮助到你

Answer 2

使用C#的一个解决方案是导入Microsoft.SqlServer.TransactSql.ScriptDom(我找到了dll C:\Program Files (x86)\Microsoft SQL Server\120\SDK\Assemblies\Microsoft.SqlServer.TransactSql.ScriptDom.dll),然后执行以下操作:

private List<string> GetTableNamesFromQueryString(string query)
{
    IList<ParseError> errors = new List<ParseError>();
    IList<TSqlParserToken> queryTokens;
    List<string> output = new List<string>(16);
    StringBuilder sb = new StringBuilder(128);
    TSql120Parser parser = new TSql120Parser(true);
    TSqlTokenType[] fromTokenTypes = new TSqlTokenType[2]
        {
            TSqlTokenType.From,
            TSqlTokenType.Join
        };
    TSqlTokenType[] identifierTokenTypes = new TSqlTokenType[2]
        {
            TSqlTokenType.Identifier,
            TSqlTokenType.QuotedIdentifier
        };

    using (System.IO.TextReader tReader = new System.IO.StringReader(query))
    {
        queryTokens = parser.GetTokenStream(tReader, out errors);
        if (errors.Count > 0) { return errors.Select(e=>"Error: " + e.Number + " Line: " + e.Line + " Column: " + e.Column + " Offset: " + e.Offset + " Message: " + e.Message).ToList(); }

        for (int i = 0; i < queryTokens.Count; i++)
        {
            if(fromTokenTypes.Contains(queryTokens[i].TokenType))
            {
                for (int j = i + 1; j < queryTokens.Count; j++)
                {
                    if (queryTokens[j].TokenType == TSqlTokenType.WhiteSpace) { continue; }
                    else if (identifierTokenTypes.Contains(queryTokens[j].TokenType))
                    {
                        sb.Clear();

                        GetQuotedIdentifier(queryTokens[j], sb);            //Change Identifiers to QuotedIdentifier (text only)

                        while (j + 2 < queryTokens.Count && queryTokens[j + 1].TokenType == TSqlTokenType.Dot && identifierTokenTypes.Contains(queryTokens[j + 2].TokenType))
                        {
                            sb.Append(queryTokens[j + 1].Text);
                            GetQuotedIdentifier(queryTokens[j + 2], sb);    //Change Identifiers to QuotedIdentifier (text only)

                            j += 2;
                        }

                        output.Add(sb.ToString());
                        break;              //exit the loop
                    }
                    else { break; }             //exit the loop if token is not a FROM, a JOIN, or white space.
                }

            }
        }

        return output.Distinct().OrderBy(tableName => tableName).ToList();
    }
}

private void GetQuotedIdentifier(TSqlParserToken token, StringBuilder sb)
{
    switch(token.TokenType)
    {
        case TSqlTokenType.Identifier: sb.Append('[').Append(token.Text).Append(']'); return;
        case TSqlTokenType.QuotedIdentifier: sb.Append(token.Text); return;
        default: throw new ArgumentException("Error: expected TokenType of token should be TSqlTokenType.Identifier or TSqlTokenType.QuotedIdentifier");
    }
}

在尝试将这个答案付诸实践后,我想出了这个.