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POWeird Select/Delete query generation in Linq2SQL
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copied!<p>For some or other reason Linq2SQL generates the following on 1 of my tables for a delete:</p> <pre><code>DELETE FROM [dbo].[Tag] WHERE ([TagId] = @p0) AND ([Type] = @p1) -- @p0: Input UniqueIdentifier (Size = 0; Prec = 0; Scale = 0) [fb538481-562d-45f2-bb33-3296cd7d0b28] -- @p1: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [1] -- @p2: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [0] -- @p3: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [7] -- @p4: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [5] -- @p5: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [8] -- @p6: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [4] -- @p7: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [3] -- @p8: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [9] -- @p9: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [6] -- @p10: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [1] -- @p11: Input TinyInt (Size = 1; Prec = 0; Scale = 0) [2] -- Context: SqlProvider(Sql2008) Model: AttributedMetaModel Build: 3.5.30729.1 </code></pre> <p>As one can see, the first 2 parameters (@p0 and @p1) are correct, but then it generates a randomized set of the unique number from 0 to 9.</p> <p>Now this does not affect the query/behaviour in any way, I am just interested in whats going on here. </p> <p><strong>UPDATE:</strong></p> <p>Tag is a base class for Linq2SQL inheritence. It seems the extra parameters are the integer values of the discriminator (Type) of all the inherited types. If I remove inherited types, the extra parameters goes down.</p> <p><strong>UPDATE 2:</strong></p> <p>I have noticed this happens for SELECT's too.</p> <pre><code>SELECT (CASE WHEN EXISTS( SELECT NULL AS [EMPTY] FROM [Tag] AS [t0] WHERE ([t0].[TagId] = @p0) AND ([t0].[TagType] = @p1) ) THEN 1 ELSE 0 END) AS [value] -- @p0: Input Guid (Size = 0; Prec = 0; Scale = 0) [60000000-0000-0000-0000-fe0000000025] -- @p1: Input Byte (Size = 0; Prec = 0; Scale = 0) [25] -- @p2: Input Byte (Size = 0; Prec = 0; Scale = 0) [0] -- @p3: Input Byte (Size = 0; Prec = 0; Scale = 0) [10] -- @p4: Input Byte (Size = 0; Prec = 0; Scale = 0) [28] -- @p5: Input Byte (Size = 0; Prec = 0; Scale = 0) [13] -- @p6: Input Byte (Size = 0; Prec = 0; Scale = 0) [27] -- @p7: Input Byte (Size = 0; Prec = 0; Scale = 0) [1] -- @p8: Input Byte (Size = 0; Prec = 0; Scale = 0) [2] -- @p9: Input Byte (Size = 0; Prec = 0; Scale = 0) [3] -- @p10: Input Byte (Size = 0; Prec = 0; Scale = 0) [4] -- @p11: Input Byte (Size = 0; Prec = 0; Scale = 0) [5] -- @p12: Input Byte (Size = 0; Prec = 0; Scale = 0) [6] -- @p13: Input Byte (Size = 0; Prec = 0; Scale = 0) [7] -- @p14: Input Byte (Size = 0; Prec = 0; Scale = 0) [8] -- @p15: Input Byte (Size = 0; Prec = 0; Scale = 0) [9] -- @p16: Input Byte (Size = 0; Prec = 0; Scale = 0) [11] -- @p17: Input Byte (Size = 0; Prec = 0; Scale = 0) [12] -- @p18: Input Byte (Size = 0; Prec = 0; Scale = 0) [14] -- @p19: Input Byte (Size = 0; Prec = 0; Scale = 0) [15] -- @p20: Input Byte (Size = 0; Prec = 0; Scale = 0) [16] -- @p21: Input Byte (Size = 0; Prec = 0; Scale = 0) [17] -- @p22: Input Byte (Size = 0; Prec = 0; Scale = 0) [18] -- @p23: Input Byte (Size = 0; Prec = 0; Scale = 0) [19] -- @p24: Input Byte (Size = 0; Prec = 0; Scale = 0) [20] -- @p25: Input Byte (Size = 0; Prec = 0; Scale = 0) [21] -- @p26: Input Byte (Size = 0; Prec = 0; Scale = 0) [22] -- @p27: Input Byte (Size = 0; Prec = 0; Scale = 0) [23] -- @p28: Input Byte (Size = 0; Prec = 0; Scale = 0) [24] -- @p29: Input Byte (Size = 0; Prec = 0; Scale = 0) [26] -- Context: SqlProvider(SqlCE) Model: AttributedMetaModel Build: 3.5.30729.1 </code></pre> <p>Just to note. I am using an enum for the discriminator, as per the MS examples.</p> <p><strong>UPDATE 3</strong></p> <p>Now I am running a SQL profiler, and I am seeing the following, and it's pretty worrying :(</p> <pre><code>exec sp_executesql N'SELECT (CASE WHEN EXISTS( SELECT NULL AS [EMPTY] FROM [Tag] AS [t0] WHERE ([t0].[TagId] = @p0) AND ([t0].[TagType] = @p1) ) THEN 1 ELSE 0 END) AS [value]', N'@p0 uniqueidentifier, @p1 tinyint, @p2 tinyint, @p3 tinyint, @p4 tinyint, @p5 tinyint, @p6 tinyint, @p7 tinyint, @p8 tinyint, @p9 tinyint, @p10 tinyint, @p11 tinyint, @p12 tinyint, @p13 tinyint, @p14 tinyint, @p15 tinyint, @p16 tinyint, @p17 tinyint, @p18 tinyint, @p19 tinyint, @p20 tinyint, @p21 tinyint, @p22 tinyint, @p23 tinyint, @p24 tinyint, @p25 tinyint, @p26 tinyint, @p27 tinyint, @p28 tinyint, @p29 tinyint, @p30 tinyint, @p31 tinyint, @p32 tinyint', @p0='60000000-0000-0000-0000-FE0000000025', @p1=25,@p2=0,@p3=23,@p4=29,@p5=31,@p6=16,@p7=14,@p8=1,@p9=2, @p10=3,@p11=4,@p12=5,@p13=6,@p14=7,@p15=8,@p16=9,@p17=10,@p18=11, @p19=12,@p20=13,@p21=22,@p22=15,@p23=17,@p24=18,@p25=19,@p26=20, @p27=21,@p28=27,@p29=24,@p30=26,@p31=30,@p32=28 </code></pre> <p>Thanks</p> <p>leppie</p>

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