/// <summary>
/// Count 函数解释。
/// </summary>
/// <param name="D">FunDescription 对象。</param>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
protected virtual string CountParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
if (D.Parameter is IDescription)
{ // 参数为表达式或都字段。
IDescription pDes = (IDescription)(D.Parameter);
pDes.DescriptionParserAdapter = D.DescriptionParserAdapter;
string param_buf = pDes.GetParser().Parsing(ref DbParameters);
if (param_buf[0] == (char)0x20)
{
param_buf = param_buf.Remove(0, 1);
}
return(string.Format("COUNT({0})", param_buf));
}
else if (D.Parameter is string || D.Parameter is char)
{
string param_v = D.Parameter.ToString();
if (param_v == "*")
{ // COUNT(*) 解释。
return("COUNT(*)");
}
else
{
throw new Exception("Count 函数使用了不正确的参数。");
}
}
else
{ // 其它情况。
IDbDataParameter p = Adapter.CreateDbParameter("uf_count", D.Parameter);
AddDbParameter(ref DbParameters, p);
return(string.Format("COUNT({0})", p.ParameterName));
}
}
/// <summary>
/// 解释当前的函数语句。
/// </summary>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
public override string Parsing(ref List <IDbDataParameter> DbParameters)
{
FunDescription FunD = (FunDescription)this.Description;
switch (FunD.FunctionName)
{
case "DISTINCT":
return(DistinctParsing(FunD, ref DbParameters));
case "COUNT":
return(CountParsing(FunD, ref DbParameters));
case "SUM":
return(SumParsing(FunD, ref DbParameters));
case "AVG":
return(AvgParsing(FunD, ref DbParameters));
case "MAX":
return(MaxParsing(FunD, ref DbParameters));
case "MIN":
return(MinParsing(FunD, ref DbParameters));
case "NOW":
return(NowParsing(FunD, ref DbParameters));
case "LEN":
return(LenParsing(FunD, ref DbParameters));
case "SUBSTRING":
return(SubstringParsing(FunD, ref DbParameters));
case "IN":
return(InParsing(FunD, ref DbParameters));
case "NOTIN":
return(NotInParsing(FunD, ref DbParameters));
case "ISNULL":
return(IsNullParsing(FunD, ref DbParameters));
case "ISNOTNULL":
return(IsNotNullParsing(FunD, ref DbParameters));
case "BETWEENAND":
return(BetweenAndParsing(FunD, ref DbParameters));
case "NOTBETWEENAND":
return(NotBetweenAndParsing(FunD, ref DbParameters));
default:
throw new NotSupportedException(string.Format("使用了未受支持的函数：{0}", FunD.FunctionName));
}
}
/// <summary>
/// 解释当前的函数语句。
/// </summary>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
public override string Parsing(ref List <IDbDataParameter> DbParameters)
{
FunDescription FunD = (FunDescription)this.Description;
switch (FunD.FunctionName)
{
case "DATEPART":
return(DatePartParsing(FunD, ref DbParameters));
default:
return(base.Parsing(ref DbParameters));
}
}
/// <summary>
/// IsNotNull 函数解释。
/// </summary>
/// <param name="D">FunDescription 对象。</param>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
protected virtual string IsNotNullParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
if (D.Parameter is FieldDescription)
{
FieldDescription desObject = (FieldDescription)(D.Parameter);
desObject.DescriptionParserAdapter = D.DescriptionParserAdapter;
StringBuilder cBuffer = new StringBuilder(desObject.GetParser().Parsing(ref DbParameters));
cBuffer.Append(" IS NOT NULL");
return(cBuffer.ToString());
}
else
{
throw new Exception("IsNotNull 函数的参数必须是一个字段类型。");
}
}
/// <summary>
/// NotIn 函数解释。
/// </summary>
/// <param name="D">FunDescription 对象。</param>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
protected virtual string NotInParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
object[] values = (object[])D.Parameter;
StringBuilder cBuffer = new StringBuilder();
FieldDescription fd = (FieldDescription)values[0];
fd.DescriptionParserAdapter = D.DescriptionParserAdapter;
cBuffer.Append(fd.GetParser().Parsing(ref DbParameters));
cBuffer.Append(" NOT IN (");
bool AppendComma = false; // 是否加逗号标识。
for (int i = 1; i < values.Length; ++i)
{
string buf;
if (values[i] is IDescription)
{
IDescription desObject = (IDescription)values[i];
desObject.DescriptionParserAdapter = D.DescriptionParserAdapter;
buf = desObject.GetParser().Parsing(ref DbParameters);
if (buf[0] == (char)0x20)
{
buf = buf.Remove(0, 1);
}
}
else
{
IDbDataParameter p = Adapter.CreateDbParameter(string.Format("uf_inValue{0}", i), values[i]);
AddDbParameter(ref DbParameters, p);
buf = p.ParameterName;
}
if (AppendComma)
{
cBuffer.AppendFormat(", {0}", buf);
}
else
{
cBuffer.Append(buf);
AppendComma = true;
}
}
cBuffer.Append(")");
return(cBuffer.ToString());
}
/// <summary>
/// Len 函数解释。
/// </summary>
/// <param name="D"></param>
/// <param name="DbParameters"></param>
/// <returns></returns>
protected override string LenParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
if (D.Parameter is IDescription)
{
IDescription desObject = (IDescription)(D.Parameter);
desObject.DescriptionParserAdapter = D.DescriptionParserAdapter;
string buf = desObject.GetParser().Parsing(ref DbParameters);
if (buf[0] == (char)0x20)
{
buf = buf.Remove(0, 1);
}
return(string.Format("LEN({0})", buf));
}
else
{
IDbDataParameter p = Adapter.CreateDbParameter("uf_len_param", D.Parameter);
AddDbParameter(ref DbParameters, p);
return(string.Format("LEN({0})", p.ParameterName));
}
}
/// <summary>
/// Sum 函数解释。
/// </summary>
/// <param name="D">FunDescription 对象。</param>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
protected virtual string SumParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
if (D.Parameter is IDescription)
{ // 参数为表达式或都字段。
IDescription pDes = (IDescription)(D.Parameter);
pDes.DescriptionParserAdapter = D.DescriptionParserAdapter;
string param_buf = pDes.GetParser().Parsing(ref DbParameters);
if (param_buf[0] == (char)0x20)
{
param_buf = param_buf.Remove(0, 1);
}
return(string.Format("SUM({0})", param_buf));
}
else
{ // 其它情况。
IDbDataParameter p = Adapter.CreateDbParameter("uf_sum", D.Parameter);
AddDbParameter(ref DbParameters, p);
return(string.Format("SUM({0})", p.ParameterName));
}
}
/// <summary>
/// Substring 函数解释。
/// </summary>
/// <param name="D"></param>
/// <param name="DbParameters"></param>
/// <returns></returns>
protected override string SubstringParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
object[] ps = (object[])D.Parameter;
if (ps[0] is IDescription)
{
IDescription desObject = (IDescription)ps[0];
desObject.DescriptionParserAdapter = D.DescriptionParserAdapter;
string buf = desObject.GetParser().Parsing(ref DbParameters);
if (buf[0] == (char)0x20)
{
buf = buf.Remove(0, 1);
}
return(string.Format("SUBSTRING({0}, {1}, {2})", buf, ps[1], ps[2]));
}
else
{
IDbDataParameter p = Adapter.CreateDbParameter("uf_substring", ps[0]);
AddDbParameter(ref DbParameters, p);
return(string.Format("SUBSTRING({0}, {1}, {2})", p.ParameterName, ps[1], ps[2]));
}
}
/// <summary>
/// NotBetweenAnd 函数解释。
/// </summary>
/// <param name="D">FunDescription 对象。</param>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
protected virtual string NotBetweenAndParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
object[] values = (object[])D.Parameter;
IDescription desObject = (IDescription)values[0];
desObject.DescriptionParserAdapter = D.DescriptionParserAdapter;
string buf = desObject.GetParser().Parsing(ref DbParameters);
if (buf[0] == (char)0x20)
{
buf = buf.Remove(0, 1);
}
StringBuilder cBuffer = new StringBuilder(buf);
IDbDataParameter p1 = Adapter.CreateDbParameter("uf_start", values[1]);
AddDbParameter(ref DbParameters, p1);
cBuffer.AppendFormat(" NOT BETWEEN {0}", p1.ParameterName);
IDbDataParameter p2 = Adapter.CreateDbParameter("uf_end", values[2]);
AddDbParameter(ref DbParameters, p2);
cBuffer.AppendFormat(" AND {0}", p2.ParameterName);
return(cBuffer.ToString());
}
/// <summary>
/// Distinct 去重复值函数解释。
/// </summary>
/// <param name="D">FunDescription 对象。</param>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
protected virtual string DistinctParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
FieldDescription[] fields = D.Parameter as FieldDescription[];
if (fields != null)
{
StringBuilder buf = new StringBuilder("DISTINCT ");
fields[0].DescriptionParserAdapter = D.DescriptionParserAdapter;
buf.Append(fields[0].GetParser().Parsing(ref DbParameters));
if (fields.Length > 1)
{
for (int i = 1; i < fields.Length; ++i)
{
fields[i].DescriptionParserAdapter = D.DescriptionParserAdapter;
buf.AppendFormat(", {0}", fields[i].GetParser().Parsing(ref DbParameters));
}
}
return(buf.ToString());
}
else
{
return(null);
}
}
/// <summary>
/// Now 函数解释。
/// </summary>
/// <param name="D"></param>
/// <param name="DbParameters"></param>
/// <returns></returns>
protected override string NowParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
return("GETDATE()");
}
/// <summary>
/// DatePart 函数解释。
/// </summary>
/// <param name="D"></param>
/// <param name="DbParameters"></param>
/// <returns></returns>
protected string DatePartParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
object[] arry = (object[])D.Parameter;
StringBuilder fBuffer = new StringBuilder("DATEPART(");
switch ((DateInterval)arry[0])
{
case DateInterval.Year:
fBuffer.Append("YYYY, ");
break;
case DateInterval.Quarter:
fBuffer.Append("QQ, ");
break;
case DateInterval.Month:
fBuffer.Append("MM, ");
break;
case DateInterval.Day:
fBuffer.Append("DD, ");
break;
case DateInterval.DayOfYear:
fBuffer.Append("DY, ");
break;
case DateInterval.Week:
fBuffer.Append("WW, ");
break;
case DateInterval.WeekDay:
fBuffer.Append("DW, ");
break;
case DateInterval.Hour:
fBuffer.Append("HH, ");
break;
case DateInterval.Minute:
fBuffer.Append("MI, ");
break;
case DateInterval.Second:
fBuffer.Append("SS, ");
break;
default:
fBuffer.Append("MS, ");
break;
}
if (arry[1] is IDescription)
{
IDescription desObject = (IDescription)arry[1];
desObject.DescriptionParserAdapter = D.DescriptionParserAdapter;
fBuffer.AppendFormat(((IDescription)arry[1]).GetParser().Parsing(ref DbParameters));
}
else
{
IDbDataParameter p = Adapter.CreateDbParameter("uf_datepart", arry[1]);
AddDbParameter(ref DbParameters, p);
fBuffer.AppendFormat("{0}", p.ParameterName);
}
fBuffer.Append(")");
return(fBuffer.ToString());
}
/// <summary>
/// Now 函数解释。
/// </summary>
/// <param name="D"></param>
/// <param name="DbParameters"></param>
/// <returns></returns>
protected override string NowParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
return("DATETIME(CURRENT_TIMESTAMP, 'localtime')");
}
protected virtual string SubstringParsing(FunDescription D, ref List <IDbDataParameter> DbParameters)
{
throw new NotSupportedException("使用了未被实现的函数：Substring");
}
