从数据库导出数据-Java 学习之路

我在数据库中有很少的表拥有大量数据 . 我的需要是

1：查询数据存在超过一年 .

2：导出并将其存档到某个文件 .

3：在任何时候我都可以将这些数据插回数据库 .

数据可能包含也可能不包含COMMA，因此不确定是否应将它们导出为csv格式 .

Which is the best file format I should go for ??

What should be the file size limitation here ??

2 回答

此脚本将指定表中的行导出到任何表结构的INSERT语句 . 所以，你只需要复制结果并在SSMS的sql文件中运行它 -

DECLARE 
      @TableName SYSNAME
    , @ObjectID INT
    , @IsImportIdentity BIT = 1

DECLARE [tables] CURSOR READ_ONLY FAST_FORWARD LOCAL FOR 
    SELECT 
          '[' + s.name + '].[' + t.name + ']'
        , t.[object_id]
    FROM (
        SELECT DISTINCT
              t.[schema_id]
            , t.[object_id]
            , t.name
        FROM sys.objects t WITH (NOWAIT)
        JOIN sys.partitions p WITH (NOWAIT) ON p.[object_id] = t.[object_id]
        WHERE p.[rows] > 0
            AND t.[type] = 'U'
    ) t
    JOIN sys.schemas s WITH (NOWAIT) ON t.[schema_id] = s.[schema_id]
    WHERE t.name IN ('<your table name>')

OPEN [tables]

FETCH NEXT FROM [tables] INTO 
      @TableName
    , @ObjectID

DECLARE 
      @SQLInsert NVARCHAR(MAX)
    , @SQLColumns NVARCHAR(MAX)
    , @SQLTinyColumns NVARCHAR(MAX)

WHILE @@FETCH_STATUS = 0 BEGIN

    SELECT 
          @SQLInsert = ''
        , @SQLColumns = ''
        , @SQLTinyColumns = ''

    ;WITH cols AS 
    (
        SELECT 
              c.name
            , datetype = t.name
            , c.column_id
        FROM sys.columns c WITH (NOWAIT)
        JOIN sys.types t WITH (NOWAIT) ON c.system_type_id = t.system_type_id AND c.user_type_id = t.user_type_id
        WHERE c.[object_id] = @ObjectID
            AND (c.is_identity = 0 OR @IsImportIdentity = 1)
            AND c.is_computed = 0
            AND t.name NOT IN ('xml', 'geography', 'geometry', 'hierarchyid')
    )
    SELECT 
          @SQLInsert = 'INSERT INTO ' + @TableName + ' (' + STUFF((
            SELECT ', [' + c.name + ']'
            FROM cols c
            ORDER BY c.column_id
            FOR XML PATH, TYPE, ROOT).value('.', 'NVARCHAR(MAX)'), 1, 2, '') + ')'
        , @SQLTinyColumns = STUFF((
            SELECT ', ' + c.name
            FROM cols c
            ORDER BY c.column_id
            FOR XML PATH, TYPE, ROOT).value('.', 'NVARCHAR(MAX)'), 1, 2, '')
        , @SQLColumns = STUFF((SELECT CHAR(13) +
            CASE 
                WHEN c.datetype = 'uniqueidentifier' 
                    THEN ' + '', '' + ISNULL('''''''' + CAST([' + c.name + '] AS VARCHAR(MAX)) + '''''''', ''NULL'')' 
                WHEN c.datetype IN ('nvarchar', 'varchar', 'nchar', 'char', 'varbinary', 'binary') 
                    THEN ' + '', '' + ISNULL('''''''' + CAST(REPLACE([' + c.name + '], '''''''', '''''''''''' ) AS NVARCHAR(MAX)) + '''''''', ''NULL'')' 
                WHEN c.datetype = 'datetime'
                    THEN ' + '', '' + ISNULL('''''''' + CONVERT(VARCHAR, [' + c.name + '], 120) + '''''''', ''NULL'')' 
                ELSE 
                ' + '', '' + ISNULL(CAST([' + c.name + '] AS NVARCHAR(MAX)), ''NULL'')'
            END
            FROM cols c
            ORDER BY c.column_id
            FOR XML PATH, TYPE, ROOT).value('.', 'NVARCHAR(MAX)'), 1, 10, 'CHAR(13) + '', ('' +')

    DECLARE @SQL NVARCHAR(MAX) = '    
    SET NOCOUNT ON;
    DECLARE 
          @SQL NVARCHAR(MAX) = ''''
        , @x INT = 1
        , @count INT = (SELECT COUNT(1) FROM ' + @TableName + ')

    IF EXISTS(
        SELECT 1
        FROM tempdb.dbo.sysobjects
        WHERE ID = OBJECT_ID(''tempdb..#import'')
    )
        DROP TABLE #import;

    SELECT ' + @SQLTinyColumns + ', ''RowNumber'' = ROW_NUMBER() OVER (ORDER BY ' + @SQLTinyColumns + ')
    INTO #import
    FROM ' + @TableName + ' 

    WHILE @x < @count BEGIN

        SELECT @SQL = ''VALUES '' + STUFF((
        SELECT ' + @SQLColumns + ' + '')''' + '
        FROM #import 
        WHERE RowNumber BETWEEN @x AND @x + 9
        FOR XML PATH, TYPE, ROOT).value(''.'', ''NVARCHAR(MAX)''), 1, 2, CHAR(13) + '' '') + '';''

        PRINT(''' + @SQLInsert + ''')
        PRINT(@SQL)

        SELECT @x = @x + 10

    END'

    EXEC sys.sp_executesql @SQL

    FETCH NEXT FROM [tables] INTO 
          @TableName
        , @ObjectID

END

CLOSE [tables]
DEALLOCATE [tables]

在输出中你得到这样的东西（AdventureWorks.Person.Address）：

INSERT INTO [Person].[Address] ([AddressID], [AddressLine1], [AddressLine2], [City], [StateProvinceID], [PostalCode], [rowguid], [ModifiedDate])
VALUES 
  (1, '1970 Napa Ct.', NULL, 'Bothell', 79, '98011', '9AADCB0D-36CF-483F-84D8-585C2D4EC6E9', '2002-01-04 00:00:00')
, (2, '9833 Mt. Dias Blv.', NULL, 'Bothell', 79, '98011', '32A54B9E-E034-4BFB-B573-A71CDE60D8C0', '2003-01-01 00:00:00')
, (3, '7484 Roundtree Drive', NULL, 'Bothell', 79, '98011', '4C506923-6D1B-452C-A07C-BAA6F5B142A4', '2007-04-08 00:00:00')
, (4, '9539 Glenside Dr', NULL, 'Bothell', 79, '98011', 'E5946C78-4BCC-477F-9FA1-CC09DE16A880', '2003-03-07 00:00:00')
, (5, '1226 Shoe St.', NULL, 'Bothell', 79, '98011', 'FBAFF937-4A97-4AF0-81FD-B849900E9BB0', '2003-01-20 00:00:00')
, (6, '1399 Firestone Drive', NULL, 'Bothell', 79, '98011', 'FEBF8191-9804-44C8-877A-33FDE94F0075', '2003-03-17 00:00:00')
, (7, '5672 Hale Dr.', NULL, 'Bothell', 79, '98011', '0175A174-6C34-4D41-B3C1-4419CD6A0446', '2004-01-12 00:00:00')
, (8, '6387 Scenic Avenue', NULL, 'Bothell', 79, '98011', '3715E813-4DCA-49E0-8F1C-31857D21F269', '2003-01-18 00:00:00')
, (9, '8713 Yosemite Ct.', NULL, 'Bothell', 79, '98011', '268AF621-76D7-4C78-9441-144FD139821A', '2006-07-01 00:00:00')
, (10, '250 Race Court', NULL, 'Bothell', 79, '98011', '0B6B739D-8EB6-4378-8D55-FE196AF34C04', '2003-01-03 00:00:00');

UPDATE:

对于任何表结构，此脚本在输出窗口中将指定表中的行导出为CSV格式 .

DECLARE 
      @TableName SYSNAME
    , @ObjectID INT

DECLARE [tables] CURSOR READ_ONLY FAST_FORWARD LOCAL FOR 
    SELECT 
          '[' + s.name + '].[' + t.name + ']'
        , t.[object_id]
    FROM (
        SELECT DISTINCT
              t.[schema_id]
            , t.[object_id]
            , t.name
        FROM sys.objects t WITH (NOWAIT)
        JOIN sys.partitions p WITH (NOWAIT) ON p.[object_id] = t.[object_id]
        WHERE p.[rows] > 0
            AND t.[type] = 'U'
    ) t
    JOIN sys.schemas s WITH (NOWAIT) ON t.[schema_id] = s.[schema_id]
    WHERE t.name IN ('<your table name>')

OPEN [tables]

FETCH NEXT FROM [tables] INTO 
      @TableName
    , @ObjectID

DECLARE 
      @SQLInsert NVARCHAR(MAX)
    , @SQLColumns NVARCHAR(MAX)
    , @SQLTinyColumns NVARCHAR(MAX)

WHILE @@FETCH_STATUS = 0 BEGIN

    SELECT 
          @SQLInsert = ''
        , @SQLColumns = ''
        , @SQLTinyColumns = ''

    ;WITH cols AS 
    (
        SELECT 
              c.name
            , datetype = t.name
            , c.column_id
        FROM sys.columns c WITH (NOWAIT)
        JOIN sys.types t WITH (NOWAIT) ON c.system_type_id = t.system_type_id AND c.user_type_id = t.user_type_id
        WHERE c.[object_id] = @ObjectID
            AND c.is_computed = 0
            AND t.name NOT IN ('xml', 'geography', 'geometry', 'hierarchyid')
    )
    SELECT 
          @SQLTinyColumns = STUFF((
            SELECT ', [' + c.name + ']'
            FROM cols c
            ORDER BY c.column_id
            FOR XML PATH, TYPE, ROOT).value('.', 'NVARCHAR(MAX)'), 1, 2, '')
        , @SQLColumns = STUFF((SELECT CHAR(13) +
            CASE 
                WHEN c.datetype = 'uniqueidentifier' 
                    THEN ' + '';'' + ISNULL('''' + CAST([' + c.name + '] AS VARCHAR(MAX)) + '''', ''NULL'')' 
                WHEN c.datetype IN ('nvarchar', 'varchar', 'nchar', 'char', 'varbinary', 'binary') 
                    THEN ' + '';'' + ISNULL('''' + CAST(REPLACE([' + c.name + '], '''', '''''''') AS NVARCHAR(MAX)) + '''', ''NULL'')' 
                WHEN c.datetype = 'datetime'
                    THEN ' + '';'' + ISNULL('''' + CONVERT(VARCHAR, [' + c.name + '], 120) + '''', ''NULL'')' 
                ELSE 
                ' + '';'' + ISNULL(CAST([' + c.name + '] AS NVARCHAR(MAX)), ''NULL'')'
            END
            FROM cols c
            ORDER BY c.column_id
            FOR XML PATH, TYPE, ROOT).value('.', 'NVARCHAR(MAX)'), 1, 10, 'CHAR(13) + '''' +')

    DECLARE @SQL NVARCHAR(MAX) = '    
    SET NOCOUNT ON;
    DECLARE 
          @SQL NVARCHAR(MAX) = ''''
        , @x INT = 1
        , @count INT = (SELECT COUNT(1) FROM ' + @TableName + ')

    IF EXISTS(
        SELECT 1
        FROM tempdb.dbo.sysobjects
        WHERE ID = OBJECT_ID(''tempdb..#import'')
    )
        DROP TABLE #import;

    SELECT ' + @SQLTinyColumns + ', ''RowNumber'' = ROW_NUMBER() OVER (ORDER BY ' + @SQLTinyColumns + ')
    INTO #import
    FROM ' + @TableName + ' 

    WHILE @x < @count BEGIN

        SELECT @SQL = STUFF((
        SELECT ' + @SQLColumns + ' + ''''' + '
        FROM #import 
        WHERE RowNumber BETWEEN @x AND @x + 9
        FOR XML PATH, TYPE, ROOT).value(''.'', ''NVARCHAR(MAX)''), 1, 1, '''')

        PRINT(@SQL)

        SELECT @x = @x + 10

    END'

    EXEC sys.sp_executesql @SQL

    FETCH NEXT FROM [tables] INTO 
          @TableName
        , @ObjectID

END

CLOSE [tables]
DEALLOCATE [tables]

在输出中你得到这样的东西（AdventureWorks.Person.Person）：

1;EM;0;NULL;Ken;J;Sánchez;NULL;0;92C4279F-1207-48A3-8448-4636514EB7E2;2003-02-08 00:00:00
2;EM;0;NULL;Terri;Lee;Duffy;NULL;1;D8763459-8AA8-47CC-AFF7-C9079AF79033;2002-02-24 00:00:00
3;EM;0;NULL;Roberto;NULL;Tamburello;NULL;0;E1A2555E-0828-434B-A33B-6F38136A37DE;2001-12-05 00:00:00
4;EM;0;NULL;Rob;NULL;Walters;NULL;0;F2D7CE06-38B3-4357-805B-F4B6B71C01FF;2001-12-29 00:00:00
5;EM;0;Ms.;Gail;A;Erickson;NULL;0;F3A3F6B4-AE3B-430C-A754-9F2231BA6FEF;2002-01-30 00:00:00
6;EM;0;Mr.;Jossef;H;Goldberg;NULL;0;0DEA28FD-EFFE-482A-AFD3-B7E8F199D56F;2002-02-17 00:00:00

回复于 2024-05-03T01:52:52+08:00

0

尝试使用 bcp 命令行实用程序，它非常有效地处理大型数据集的导入/导出：

bcp“select * from [YourTable]”queryout data.dat -n -S YourServer -d“YourDatabase”-T

-T表示受信任的身份验证 . -n表示原生格式，因此您不必担心数据类型，逗号等 . 但是，这确实意味着您无法在编辑器中查看数据;它只能用于加载回SQL Server . 如果您想要CSV格式，可以使用-c .

要导入：

bcp“[YourTable]”在data.dat -n -S YourServer -d“YourDatabase”-T中

回复于 2024-05-03T01:52:52+08:00

从数据库导出数据

2 回答

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