关于SQL一对多关系转换的效率思考（续）

View Code51Testing软件测试网Bx*jsS1f'Y+`

&e1z1{4M;^z0    /// <summary>51Testing软件测试网@M7R~PC ]C}R
    /// The variable that holds the intermediate result of the concatenation
$~'kDT8LE.g0    /// </summary>
F'QB1j.Vz&z9@mx5s0    private StringBuilder intermediateResult;51Testing软件测试网 Rt0Hs \?3l

`,I-d)Lq+u@U8B0    /// <summary>51Testing软件测试网 y#N2V v;q?T;V+z
    /// Initialize the internal data structures
%P%Q-zv"|C[bj0    /// </summary>51Testing软件测试网2dpuCz,|~5U
    public void Init()
BP8B? h(h|"x f7o"\0    {51Testing软件测试网 w4S8Y5EcWA4\Kzm
        this.intermediateResult = new StringBuilder();51Testing软件测试网V,g/D{S(G/_6Gn,]
    }

    /// <summary>51Testing软件测试网
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    /// Accumulate the next value, not if the value is null51Testing软件测试网o9Q-Q Fp-l2^_a
    /// </summary>51Testing软件测试网w~x?)L!O!le
    /// <param name="value"></param>51Testing软件测试网Zf5jU:B9^,{*}"Qr?
    public void Accumulate(SqlString value)
g3r'}3`;H*b q,a0    {
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F
^ `j|+d0        if (value.IsNull)51Testing软件测试网f ]&cXuQ
        {
~4Pef6`C&h0            return;
+`f)dLuB^0        }

        this.intermediateResult.Append(value.Value).Append(',');51Testing软件测试网[9d(r(Y/veX8J
    }

    /// <summary>
m0@Sq(W1V wL0    /// Merge the partially computed aggregate with this aggregate.51Testing软件测试网 Z+f2@/SB"J[s
    /// </summary>
J6v V(W hd!Vx0    /// <param name="other"></param>51Testing软件测试网 H3RHX zC:J a0W8S
    public void Merge(Concatenate other)51Testing软件测试网
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    {
frc?.}p5j0        this.intermediateResult.Append(other.intermediateResult);51Testing软件测试网`,vCq$GO/l\
    }51Testing软件测试网QVZ3VE

8tOo~:iu3yMN0    /// <summary>51Testing软件测试网(H1Yzd(j1h H C@T)t0|
    /// Called at the end of aggregation, to return the results of the aggregation.51Testing软件测试网1Kx]8r3mp
    /// </summary>
} c|6eA*a u8H U0    /// <returns></returns>51Testing软件测试网`2c&mAC-X
    public SqlString Terminate()
U$h2?*JJZ{,w0    {51Testing软件测试网0kGR$r#ei|n|
        string utput = string.Empty;
W p7kAn(g4t0        //delete the trailing comma, if any
%m l!U7\wV-K0        if (this.intermediateResult != null
zS}T*y}"d0            && this.intermediateResult.Length > 0)
J;zd%^6j~e0        {
,v,R!KvgC Q[0            utput = this.intermediateResult.ToString(0, this.intermediateResult.Length - 1);
G)T%O$wsku(A0        }

        return new SqlString(output);
%q?2zp(B A0    }

@4t#q-K4t:cv0    public void Read(BinaryReader r)
6I/][*A`&w+XJydFL[0    {
`-n`7Ve0s%}F0        intermediateResult = new StringBuilder(r.ReadString());
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c'P)V;J!IX0    }51Testing软件测试网q/ntBD/k"y,UF\)Y

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x0    public void Write(BinaryWriter w)

KS$}~2Eg J-Wn0    {51Testing软件测试网4ZJ9A}h"nU*s
        w.Write(this.intermediateResult.ToString());
?"u"v*dN9N0    }51Testing软件测试网$J@\~1|6S O,f