有没有办法在 SQL Server 的数据库的所有表中搜索字符串？
我想搜索字符串 say john。结果应显示包含john.
问问题
470413 次
11 回答
318
如果你和我一样，在生产环境中有一定的限制，你可能希望使用表变量而不是临时表，使用即席查询而不是创建过程。
当然根据你的 sql server 实例，它必须支持表变量。
我还添加了一条 USE 语句来缩小搜索范围
USE DATABASE_NAME
DECLARE @SearchStr nvarchar(100) = 'SEARCH_TEXT'
DECLARE @Results TABLE (ColumnName nvarchar(370), ColumnValue nvarchar(3630))
SET NOCOUNT ON
DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
WHILE @TableName IS NOT NULL
BEGIN
SET @ColumnName = ''
SET @TableName =
(
SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
AND OBJECTPROPERTY(
OBJECT_ID(
QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
), 'IsMSShipped'
) = 0
)
WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
SET @ColumnName =
(
SELECT MIN(QUOTENAME(COLUMN_NAME))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(@TableName, 2)
AND TABLE_NAME = PARSENAME(@TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar', 'int', 'decimal')
AND QUOTENAME(COLUMN_NAME) > @ColumnName
)
IF @ColumnName IS NOT NULL
BEGIN
INSERT INTO @Results
EXEC
(
'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630)
FROM ' + @TableName + ' (NOLOCK) ' +
' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
)
END
END
END
SELECT ColumnName, ColumnValue FROM @Results
于 2014-12-08T15:17:58.703 回答
51
有点晚，但希望有用。
为什么不尝试一些可以集成到 SSMS 中的第三方工具。
我使用ApexSQL Search（100% 免费）在模式和数据搜索方面都取得了很好的成功，并且还有具有此功能的SSMS 工具包（对于 SQL 2012 来说不是免费的，但相当实惠）。
上面的存储过程真的很棒；只是在我看来这更方便。此外，如果您想搜索日期时间列或 GUID 列等，则需要稍作修改......</p>
于 2013-10-01T09:28:31.663 回答
39
要更新TechDo对 SQL server 2012 的回答。您需要更改'FROM ' + @TableName + ' (NOLOCK) ' ： FROM ' + @TableName + 'WITH (NOLOCK) ' +
否则，您将收到以下错误：Deprecated feature 'Table hint without WITH' is not supported in this version of SQL Server.
下面是完整的更新存储过程：
CREATE PROC SearchAllTables
(
@SearchStr nvarchar(100)
)
AS
BEGIN
CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))
SET NOCOUNT ON
DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
WHILE @TableName IS NOT NULL
BEGIN
SET @ColumnName = ''
SET @TableName =
(
SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
AND OBJECTPROPERTY(
OBJECT_ID(
QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
), 'IsMSShipped'
) = 0
)
WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
SET @ColumnName =
(
SELECT MIN(QUOTENAME(COLUMN_NAME))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(@TableName, 2)
AND TABLE_NAME = PARSENAME(@TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar', 'int', 'decimal')
AND QUOTENAME(COLUMN_NAME) > @ColumnName
)
IF @ColumnName IS NOT NULL
BEGIN
INSERT INTO #Results
EXEC
(
'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630)
FROM ' + @TableName + 'WITH (NOLOCK) ' +
' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
)
END
END
END
SELECT ColumnName, ColumnValue FROM #Results
END
于 2013-11-07T20:35:06.873 回答
31
有点晚了，但是您可以使用此查询轻松找到一个字符串
DECLARE
@search_string VARCHAR(100),
@table_name SYSNAME,
@table_id INT,
@column_name SYSNAME,
@sql_string VARCHAR(2000)
SET @search_string = 'StringtoSearch'
DECLARE tables_cur CURSOR FOR SELECT ss.name +'.'+ so.name [name], object_id FROM sys.objects so INNER JOIN sys.schemas ss ON so.schema_id = ss.schema_id WHERE type = 'U'
OPEN tables_cur
FETCH NEXT FROM tables_cur INTO @table_name, @table_id
WHILE (@@FETCH_STATUS = 0)
BEGIN
DECLARE columns_cur CURSOR FOR SELECT name FROM sys.columns WHERE object_id = @table_id
AND system_type_id IN (167, 175, 231, 239)
OPEN columns_cur
FETCH NEXT FROM columns_cur INTO @column_name
WHILE (@@FETCH_STATUS = 0)
BEGIN
SET @sql_string = 'IF EXISTS (SELECT * FROM ' + @table_name + ' WHERE [' + @column_name + ']
LIKE ''%' + @search_string + '%'') PRINT ''' + @table_name + ', ' + @column_name + ''''
EXECUTE(@sql_string)
FETCH NEXT FROM columns_cur INTO @column_name
END
CLOSE columns_cur
DEALLOCATE columns_cur
FETCH NEXT FROM tables_cur INTO @table_name, @table_id
END
CLOSE tables_cur
DEALLOCATE tables_cur
于 2017-08-09T08:34:00.697 回答
5
不需要嵌套循环（通过表的外部循环和通过所有表列的内部循环）。可以从一个循环中检索所有（或任意选择/过滤的）表列组合，INFORMATION_SCHEMA.COLUMNS只需通过（搜索）所有这些组合：
DECLARE @search VARCHAR(100), @table SYSNAME, @column SYSNAME
DECLARE curTabCol CURSOR FOR
SELECT c.TABLE_SCHEMA + '.' + c.TABLE_NAME, c.COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS c
JOIN INFORMATION_SCHEMA.TABLES t
ON t.TABLE_NAME=c.TABLE_NAME AND t.TABLE_TYPE='BASE TABLE' -- avoid views
WHERE c.DATA_TYPE IN ('varchar','nvarchar') -- searching only in these column types
--AND c.COLUMN_NAME IN ('NAME','DESCRIPTION') -- searching only in these column names
SET @search='john'
OPEN curTabCol
FETCH NEXT FROM curTabCol INTO @table, @column
WHILE (@@FETCH_STATUS = 0)
BEGIN
EXECUTE('IF EXISTS
(SELECT * FROM ' + @table + ' WHERE ' + @column + ' = ''' + @search + ''')
PRINT ''' + @table + '.' + @column + '''')
FETCH NEXT FROM curTabCol INTO @table, @column
END
CLOSE curTabCol
DEALLOCATE curTabCol
于 2020-05-14T13:20:18.227 回答
3
我为此编写了一个 SP，它以表名、找到搜索关键字字符串的列名以及搜索相应行的形式返回搜索结果，如下面的屏幕截图所示。
这可能不是最有效的解决方案，但您始终可以根据需要修改和使用它。
IF OBJECT_ID('sp_KeywordSearch', 'P') IS NOT NULL
DROP PROC sp_KeywordSearch
GO
CREATE PROCEDURE sp_KeywordSearch @KeyWord NVARCHAR(100)
AS
BEGIN
DECLARE @Result TABLE
(TableName NVARCHAR(300),
ColumnName NVARCHAR(MAX))
DECLARE @Sql NVARCHAR(MAX),
@TableName NVARCHAR(300),
@ColumnName NVARCHAR(300),
@Count INT
DECLARE @tableCursor CURSOR
SET @tableCursor = CURSOR LOCAL SCROLL FOR
SELECT N'SELECT @Count = COUNT(1) FROM [dbo].[' + T.TABLE_NAME + '] WITH (NOLOCK) WHERE CAST([' + C.COLUMN_NAME +
'] AS NVARCHAR(MAX)) LIKE ''%' + @KeyWord + N'%''',
T.TABLE_NAME,
C.COLUMN_NAME
FROM INFORMATION_SCHEMA.TABLES AS T WITH (NOLOCK)
INNER JOIN INFORMATION_SCHEMA.COLUMNS AS C WITH (NOLOCK)
ON T.TABLE_SCHEMA = C.TABLE_SCHEMA AND
T.TABLE_NAME = C.TABLE_NAME
WHERE T.TABLE_TYPE = 'BASE TABLE' AND
C.TABLE_SCHEMA = 'dbo' AND
C.DATA_TYPE NOT IN ('image', 'timestamp')
OPEN @tableCursor
FETCH NEXT FROM @tableCursor INTO @Sql, @TableName, @ColumnName
WHILE (@@FETCH_STATUS = 0)
BEGIN
SET @Count = 0
EXEC sys.sp_executesql
@Sql,
N'@Count INT OUTPUT',
@Count OUTPUT
IF @Count > 0
BEGIN
INSERT INTO @Result
(TableName, ColumnName)
VALUES (@TableName, @ColumnName)
END
FETCH NEXT FROM @tableCursor INTO @Sql, @TableName, @ColumnName
END
CLOSE @tableCursor
DEALLOCATE @tableCursor
SET @tableCursor = CURSOR LOCAL SCROLL FOR
SELECT SUBSTRING(TB.Sql, 1, LEN(TB.Sql) - 3) AS Sql, TB.TableName, SUBSTRING(TB.Columns, 1, LEN(TB.Columns) - 1) AS Columns
FROM (SELECT R.TableName, (SELECT R2.ColumnName + ', ' FROM @Result AS R2 WHERE R.TableName = R2.TableName FOR XML PATH('')) AS Columns,
'SELECT * FROM ' + R.TableName + ' WITH (NOLOCK) WHERE ' +
(SELECT 'CAST(' + R2.ColumnName + ' AS NVARCHAR(MAX)) LIKE ''%' + @KeyWord + '%'' OR '
FROM @Result AS R2
WHERE R.TableName = R2.TableName
FOR
XML PATH('')) AS Sql
FROM @Result AS R
GROUP BY R.TableName) TB
ORDER BY TB.Sql
OPEN @tableCursor
FETCH NEXT FROM @tableCursor INTO @Sql, @TableName, @ColumnName
WHILE (@@FETCH_STATUS = 0)
BEGIN
PRINT @Sql
SELECT @TableName AS [Table],
@ColumnName AS Columns
EXEC(@Sql)
FETCH NEXT FROM @tableCursor INTO @Sql, @TableName, @ColumnName
END
CLOSE @tableCursor
DEALLOCATE @tableCursor
END
于 2017-03-10T08:50:41.770 回答
0
这很有帮助。我想将此函数导入 Postgre SQL 数据库。以为我会与任何有兴趣的人分享。将有他们几个小时。注意：此函数创建一个可以在 Postgre 数据库上复制和执行的 SQL 语句列表。也许比我更聪明的人可以让 Postgre 在一个函数中创建和执行语句。
CREATE OR REPLACE FUNCTION SearchAllTables(_search text) RETURNS TABLE( txt text ) as $funct$
DECLARE __COUNT int;
__SQL text;
BEGIN
EXECUTE 'SELECT COUNT(0) FROM INFORMATION_SCHEMA.COLUMNS
WHERE DATA_TYPE = ''text''
AND table_schema = ''public'' ' INTO __COUNT;
RETURN QUERY
SELECT CASE WHEN ROW_NUMBER() OVER (ORDER BY table_name) < __COUNT THEN
'SELECT ''' || table_name ||'.'|| column_name || ''' AS tbl, "' || column_name || '" AS col FROM "public"."' || "table_name" || '" WHERE "'|| "column_name" || '" ILIKE ''%' || _search || '%'' UNION ALL'
ELSE
'SELECT ''' || table_name ||'.'|| column_name || ''' AS tbl, "' || column_name || '" AS col FROM "public"."' || "table_name" || '" WHERE "'|| "column_name" || '" ILIKE ''%' || _search || '%'''
END AS txt
FROM INFORMATION_SCHEMA.COLUMNS
WHERE DATA_TYPE = 'text'
AND table_schema = 'public';
END
$funct$ LANGUAGE plpgsql;
于 2018-09-05T20:41:37.657 回答
0
这篇文章中已经多次提到的答案我已经采用了一点，因为我也只需要在一个表中搜索：
（并且还使表名的输入更简单一些）
ALTER PROC dbo.db_compare_SearchAllTables_sp
(
@SearchStr nvarchar(100),
@TableName nvarchar(256) = ''
)
AS
BEGIN
if PARSENAME(@TableName, 2) is null
set @TableName = 'dbo.' + QUOTENAME(@TableName, '"')
declare @results TABLE(ColumnName nvarchar(370), ColumnValue nvarchar(3630))
SET NOCOUNT ON
DECLARE @ColumnName nvarchar(128) = '', @SearchStr2 nvarchar(110)
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
IF @TableName <> ''
WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
SET @ColumnName =
(
SELECT MIN(QUOTENAME(COLUMN_NAME))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(@TableName, 2)
AND TABLE_NAME = PARSENAME(@TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
AND QUOTENAME(COLUMN_NAME) > @ColumnName
)
IF @ColumnName IS NOT NULL
BEGIN
INSERT INTO @results
EXEC
(
'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630)
FROM ' + @TableName + ' WITH (NOLOCK) ' +
' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
)
END
END
ELSE
WHILE @TableName IS NOT NULL
BEGIN
SET @ColumnName = ''
SET @TableName =
(
SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
AND OBJECTPROPERTY(
OBJECT_ID(
QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
), 'IsMSShipped'
) = 0
)
WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
SET @ColumnName =
(
SELECT MIN(QUOTENAME(COLUMN_NAME))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(@TableName, 2)
AND TABLE_NAME = PARSENAME(@TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
AND QUOTENAME(COLUMN_NAME) > @ColumnName
)
IF @ColumnName IS NOT NULL
BEGIN
INSERT INTO @results
EXEC
(
'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630)
FROM ' + @TableName + ' WITH (NOLOCK) ' +
' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
)
END
END
END
SELECT ColumnName, ColumnValue FROM @results
END
于 2019-09-11T08:07:47.250 回答
0
改进了来自@Brandon 的惊人答案，我使用铸件向 ntext 和 xml 添加了类型：
BEGIN TRAN
DECLARE @SearchStr nvarchar(100) = 'SEARCH_TEXT'
DECLARE @Results TABLE (ColumnName nvarchar(370), ColumnValue nvarchar(3630))
SET NOCOUNT ON
DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
WHILE @TableName IS NOT NULL
BEGIN
SET @ColumnName = ''
SET @TableName =
(
SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
AND OBJECTPROPERTY(
OBJECT_ID(
QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
), 'IsMSShipped'
) = 0
)
WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
SET @ColumnName =
(
SELECT MIN(QUOTENAME(COLUMN_NAME))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(@TableName, 2)
AND TABLE_NAME = PARSENAME(@TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar', 'int', 'decimal', 'ntext', 'xml')
AND QUOTENAME(COLUMN_NAME) > @ColumnName
)
IF @ColumnName IS NOT NULL
BEGIN
INSERT INTO @Results
EXEC
(
'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT((cast(' + @ColumnName + ' as nvarchar(max))), 3630)
FROM ' + @TableName + ' (NOLOCK) ' +
' WHERE (cast(' + @ColumnName + ' as nvarchar(max))) LIKE ' + @SearchStr2
)
END
END
END
SELECT ColumnName, ColumnValue FROM @Results
ROLLBACK
于 2020-11-13T08:46:02.373 回答
0
[CREATE PROC SearchAllTables ( @SearchStr nvarchar(100) ) AS
BEGIN
CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))
SET NOCOUNT ON
DECLARE @TableName nvarchar(256),
@ColumnName nvarchar(128),
@SearchStr2 nvarchar(110)
SET @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
WHILE @TableName IS NOT NULL
BEGIN
SET @ColumnName = ''
SET @TableName = ( SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
AND OBJECTPROPERTY( OBJECT_ID( QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) ), 'IsMSShipped' ) = 0
)
WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
SET @ColumnName = ( SELECT MIN(QUOTENAME(COLUMN_NAME))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(@TableName, 2)
AND TABLE_NAME = PARSENAME(@TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
AND QUOTENAME(COLUMN_NAME) > @ColumnName )
IF @ColumnName IS NOT NULL
BEGIN
INSERT INTO #Results
EXEC ( 'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630) FROM ' + @TableName + ' (NOLOCK) ' + ' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2 )
END
END
END
SELECT ColumnName, ColumnValue FROM #Results
END
EXEC SearchAllTables 'Computer'][1]
[1]: https://koukia.ca/search-for-a-string-in-all-tables-and-all-fields-of-a-database-with-tsql-b6f8a1bfda37
于 2021-09-30T10:20:30.850 回答
0
不要放弃@Brandon 的出色回答，但 OP 要求“结果应显示表格及其各自的行”。我根据@Brandon 的原始答案创建了一个记录级解决方案，它还通过简单地将所有适当的列连接到一个字符串中来避免使用其他人在这里使用的 CURSOR。（我觉得这会表现得更好，但老实说我没有比较结果 - 随意这样做并在此处提供反馈。）
注意我使用了 STRING_AGG 函数来连接列。如果您有旧版本的 SQL Server，您可能需要使用可在线找到的替代方法之一。
CREATE PROC [dbo].[SearchAllTablesByRecord]
(
@SearchStr NVARCHAR(100)
)
AS
BEGIN
SET NOCOUNT ON
DECLARE @TableName NVARCHAR(256), @SearchStr2 NVARCHAR(110)
DECLARE @ColumnList NVARCHAR(2048), @ColumnJoin NVARCHAR(2048)
SET @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
WHILE @TableName IS NOT NULL
BEGIN
SET @TableName =
(
SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
AND OBJECTPROPERTY(
OBJECT_ID(
QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
), 'IsMSShipped'
) = 0
)
PRINT @TableName -- For progress monitoring
SET @ColumnList =
(
SELECT STRING_AGG(QUOTENAME(COLUMN_NAME),',')
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(@TableName, 2)
AND TABLE_NAME = PARSENAME(@TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
)
SET @ColumnJoin = REPLACE(@ColumnList,',','+')
IF @ColumnList <> ''
EXEC
(
'SELECT ''' + @TableName + ''' AS [Table],' + @ColumnList + '
INTO #Results
FROM ' + @TableName + ' (NOLOCK) ' +
' WHERE ' + @ColumnJoin + ' LIKE ' + @SearchStr2 + '
IF @@ROWCOUNT > 0 SELECT * FROM #Results'
)
END
END
于 2022-02-02T05:23:32.870 回答