public Declare ReadDeclare()
{
SkipComments();
Declare dec = new Declare();
Next();
var exp = ReadExpression();
if (exp is Variable vari1)
{
dec.VarName = vari1.Name;
}
else
{
ex("declare语法错误。");
}
exp = ReadExpression();
SqlDataTyoe t = new SqlDataTyoe();
if (exp is Variable vari)
{
t.DataType = SqlDataTyoe.GetDataType(vari.Name);
}
else if (exp is Function func)
{
t.DataType = SqlDataTyoe.GetDataType(func.Name);
var paras = func.Arguments?.GetList();
if (paras != null && paras.Count > 0)
{
try
{
t.Length1 = int.Parse(((Constant)paras[0]).Content);
if (paras.Count > 1)
{
t.Length2 = int.Parse(((Constant)paras[1]).Content);
if (paras.Count > 2)
{
ex($"类型[{func.Name}]的长度/精度参数错误。");
}
}
}
catch (Exception)
{
ex($"类型[{func.Name}]的长度/精度参数错误。");
}
}
}
dec.DataType = t;
return(dec);
}
public override string GetDataType(SqlDataTyoe type)
{
string t = "";
switch (type.DataType)
{
case DataType.Char:
t = "char";
break;
case DataType.VarChar:
t = "varchar";
break;
case DataType.Text:
t = "text";
break;
case DataType.Int:
t = "int";
break;
case DataType.Long:
t = "bigint";
break;
case DataType.Decimal:
t = "decimal";
break;
case DataType.Boolean:
t = "bit";
break;
case DataType.Binary:
t = "binary";
break;
case DataType.DateTime:
t = "datetime";
break;
case DataType.Time:
t = "time";
break;
default:
throw new NotSupportedException("不支持的类型：" + type.DataType.ToString());
}
string getlength(int len)
{
if (len >= 0)
{
return(len.ToString());;
}
else
{//为负表示使用最大值
return("max");
}
}
if (type.Length1.HasValue && type.Length2.HasValue)
{
return($"{t}({getlength(type.Length1.Value)},{getlength(type.Length2.Value)})");
}
else if (type.Length1.HasValue)
{
return($"{t}({getlength(type.Length1.Value)})");
}
else
{
return(t);
}
}
/// <summary> /// 在派生类中实现，获取通用数据类型在目标数据库中的实现 /// </summary> /// <param name="t"></param> /// <returns></returns> public abstract string GetDataType(SqlDataTyoe t);
