ExpressionToSQL
2024-09-02 07:20:36
ExpressionToSql
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Text; namespace test.DataAccess
{
public abstract class ExpressionVisitorSql
{
protected ExpressionVisitorSql() { } protected virtual Expression Visit(Expression exp)
{
if (exp == null)
return exp;
switch (exp.NodeType)
{
case ExpressionType.Negate:
case ExpressionType.NegateChecked:
case ExpressionType.Not:
case ExpressionType.Convert:
case ExpressionType.ConvertChecked:
case ExpressionType.ArrayLength:
case ExpressionType.Quote:
case ExpressionType.TypeAs:
return this.VisitUnary((UnaryExpression)exp);
case ExpressionType.Add:
case ExpressionType.AddChecked:
case ExpressionType.Subtract:
case ExpressionType.SubtractChecked:
case ExpressionType.Multiply:
case ExpressionType.MultiplyChecked:
case ExpressionType.Divide:
case ExpressionType.Modulo:
case ExpressionType.And:
case ExpressionType.AndAlso:
case ExpressionType.Or:
case ExpressionType.OrElse:
case ExpressionType.LessThan:
case ExpressionType.LessThanOrEqual:
case ExpressionType.GreaterThan:
case ExpressionType.GreaterThanOrEqual:
case ExpressionType.Equal:
case ExpressionType.NotEqual:
case ExpressionType.Coalesce:
case ExpressionType.ArrayIndex:
case ExpressionType.RightShift:
case ExpressionType.LeftShift:
case ExpressionType.ExclusiveOr:
return this.VisitBinary((BinaryExpression)exp);
case ExpressionType.TypeIs:
return this.VisitTypeIs((TypeBinaryExpression)exp);
case ExpressionType.Conditional:
return this.VisitConditional((ConditionalExpression)exp);
case ExpressionType.Constant:
return this.VisitConstant((ConstantExpression)exp);
case ExpressionType.Parameter:
return this.VisitParameter((ParameterExpression)exp);
case ExpressionType.MemberAccess:
return this.VisitMemberAccess((MemberExpression)exp);
case ExpressionType.Call:
return this.VisitMethodCall((MethodCallExpression)exp);
case ExpressionType.Lambda:
return this.VisitLambda((LambdaExpression)exp);
case ExpressionType.New:
return this.VisitNew((NewExpression)exp);
case ExpressionType.NewArrayInit:
case ExpressionType.NewArrayBounds:
return this.VisitNewArray((NewArrayExpression)exp);
case ExpressionType.Invoke:
return this.VisitInvocation((InvocationExpression)exp);
case ExpressionType.MemberInit:
return this.VisitMemberInit((MemberInitExpression)exp);
case ExpressionType.ListInit:
return this.VisitListInit((ListInitExpression)exp);
default:
throw new Exception(string.Format("Unhandled expression type: '{0}'", exp.NodeType));
}
} protected virtual MemberBinding VisitBinding(MemberBinding binding)
{
switch (binding.BindingType)
{
case MemberBindingType.Assignment:
return this.VisitMemberAssignment((MemberAssignment)binding);
case MemberBindingType.MemberBinding:
return this.VisitMemberMemberBinding((MemberMemberBinding)binding);
case MemberBindingType.ListBinding:
return this.VisitMemberListBinding((MemberListBinding)binding);
default:
throw new Exception(string.Format("Unhandled binding type '{0}'", binding.BindingType));
}
} protected virtual ElementInit VisitElementInitializer(ElementInit initializer)
{
ReadOnlyCollection<Expression> arguments = this.VisitExpressionList(initializer.Arguments);
if (arguments != initializer.Arguments)
{
return Expression.ElementInit(initializer.AddMethod, arguments);
}
return initializer;
} protected virtual Expression VisitUnary(UnaryExpression u)
{
Expression operand = this.Visit(u.Operand);
if (operand != u.Operand)
{
return Expression.MakeUnary(u.NodeType, operand, u.Type, u.Method);
}
return u;
} protected virtual Expression VisitBinary(BinaryExpression b)
{
Expression left = this.Visit(b.Left);
Expression right = this.Visit(b.Right);
Expression conversion = this.Visit(b.Conversion);
if (left != b.Left || right != b.Right || conversion != b.Conversion)
{
if (b.NodeType == ExpressionType.Coalesce && b.Conversion != null)
return Expression.Coalesce(left, right, conversion as LambdaExpression);
else
return Expression.MakeBinary(b.NodeType, left, right, b.IsLiftedToNull, b.Method);
}
return b;
} protected virtual Expression VisitTypeIs(TypeBinaryExpression b)
{
Expression expr = this.Visit(b.Expression);
if (expr != b.Expression)
{
return Expression.TypeIs(expr, b.TypeOperand);
}
return b;
} protected virtual Expression VisitConstant(ConstantExpression c)
{
return c;
} protected virtual Expression VisitConditional(ConditionalExpression c)
{
Expression test = this.Visit(c.Test);
Expression ifTrue = this.Visit(c.IfTrue);
Expression ifFalse = this.Visit(c.IfFalse);
if (test != c.Test || ifTrue != c.IfTrue || ifFalse != c.IfFalse)
{
return Expression.Condition(test, ifTrue, ifFalse);
}
return c;
} protected virtual Expression VisitParameter(ParameterExpression p)
{
return p;
} protected virtual Expression VisitMemberAccess(MemberExpression m)
{
Expression exp = this.Visit(m.Expression);
if (exp != m.Expression)
{
return Expression.MakeMemberAccess(exp, m.Member);
}
return m;
} protected virtual Expression VisitMethodCall(MethodCallExpression m)
{ //MethodCallExpression mce = m;
//if (mce.Method.Name == "Like")
// return string.Format("({0} like {1})", ExpressionRouter(mce.Arguments[0]), ExpressionRouter(mce.Arguments[1]));
//else if (mce.Method.Name == "NotLike")
// return string.Format("({0} Not like {1})", ExpressionRouter(mce.Arguments[0]), ExpressionRouter(mce.Arguments[1]));
//else if (mce.Method.Name == "In")
// return string.Format("{0} In ({1})", ExpressionRouter(mce.Arguments[0]), ExpressionRouter(mce.Arguments[1]));
//else if (mce.Method.Name == "NotIn")
// return string.Format("{0} Not In ({1})", ExpressionRouter(mce.Arguments[0]), ExpressionRouter(mce.Arguments[1]));
//MethodCallExpression mce = m; Expression obj = this.Visit(m.Object);
IEnumerable<Expression> args = this.VisitExpressionList(m.Arguments);
if (obj != m.Object || args != m.Arguments)
{
return Expression.Call(obj, m.Method, args);
}
return m;
} protected virtual ReadOnlyCollection<Expression> VisitExpressionList(ReadOnlyCollection<Expression> original)
{
List<Expression> list = null;
for (int i = , n = original.Count; i < n; i++)
{
Expression p = this.Visit(original[i]);
if (list != null)
{
list.Add(p);
}
else if (p != original[i])
{
list = new List<Expression>(n);
for (int j = ; j < i; j++)
{
list.Add(original[j]);
}
list.Add(p);
}
}
if (list != null)
{
return list.AsReadOnly();
}
return original;
} protected virtual MemberAssignment VisitMemberAssignment(MemberAssignment assignment)
{
Expression e = this.Visit(assignment.Expression);
if (e != assignment.Expression)
{
return Expression.Bind(assignment.Member, e);
}
return assignment;
} protected virtual MemberMemberBinding VisitMemberMemberBinding(MemberMemberBinding binding)
{
IEnumerable<MemberBinding> bindings = this.VisitBindingList(binding.Bindings);
if (bindings != binding.Bindings)
{
return Expression.MemberBind(binding.Member, bindings);
}
return binding;
} protected virtual MemberListBinding VisitMemberListBinding(MemberListBinding binding)
{
IEnumerable<ElementInit> initializers = this.VisitElementInitializerList(binding.Initializers);
if (initializers != binding.Initializers)
{
return Expression.ListBind(binding.Member, initializers);
}
return binding;
} protected virtual IEnumerable<MemberBinding> VisitBindingList(ReadOnlyCollection<MemberBinding> original)
{
List<MemberBinding> list = null;
for (int i = , n = original.Count; i < n; i++)
{
MemberBinding b = this.VisitBinding(original[i]);
if (list != null)
{
list.Add(b);
}
else if (b != original[i])
{
list = new List<MemberBinding>(n);
for (int j = ; j < i; j++)
{
list.Add(original[j]);
}
list.Add(b);
}
}
if (list != null)
return list;
return original;
} protected virtual IEnumerable<ElementInit> VisitElementInitializerList(ReadOnlyCollection<ElementInit> original)
{
List<ElementInit> list = null;
for (int i = , n = original.Count; i < n; i++)
{
ElementInit init = this.VisitElementInitializer(original[i]);
if (list != null)
{
list.Add(init);
}
else if (init != original[i])
{
list = new List<ElementInit>(n);
for (int j = ; j < i; j++)
{
list.Add(original[j]);
}
list.Add(init);
}
}
if (list != null)
return list;
return original;
} protected virtual Expression VisitLambda(LambdaExpression lambda)
{
Expression body = this.Visit(lambda.Body);
if (body != lambda.Body)
{
return Expression.Lambda(lambda.Type, body, lambda.Parameters);
}
return lambda;
} protected virtual NewExpression VisitNew(NewExpression nex)
{
IEnumerable<Expression> args = this.VisitExpressionList(nex.Arguments);
if (args != nex.Arguments)
{
if (nex.Members != null)
return Expression.New(nex.Constructor, args, nex.Members);
else
return Expression.New(nex.Constructor, args);
}
return nex;
} protected virtual Expression VisitMemberInit(MemberInitExpression init)
{
NewExpression n = this.VisitNew(init.NewExpression);
IEnumerable<MemberBinding> bindings = this.VisitBindingList(init.Bindings);
if (n != init.NewExpression || bindings != init.Bindings)
{
return Expression.MemberInit(n, bindings);
}
return init;
} protected virtual Expression VisitListInit(ListInitExpression init)
{
NewExpression n = this.VisitNew(init.NewExpression);
IEnumerable<ElementInit> initializers = this.VisitElementInitializerList(init.Initializers);
if (n != init.NewExpression || initializers != init.Initializers)
{
return Expression.ListInit(n, initializers);
}
return init;
} protected virtual Expression VisitNewArray(NewArrayExpression na)
{
IEnumerable<Expression> exprs = this.VisitExpressionList(na.Expressions);
if (exprs != na.Expressions)
{
if (na.NodeType == ExpressionType.NewArrayInit)
{
return Expression.NewArrayInit(na.Type.GetElementType(), exprs);
}
else
{
return Expression.NewArrayBounds(na.Type.GetElementType(), exprs);
}
}
return na;
} protected virtual Expression VisitInvocation(InvocationExpression iv)
{
IEnumerable<Expression> args = this.VisitExpressionList(iv.Arguments);
Expression expr = this.Visit(iv.Expression);
if (args != iv.Arguments || expr != iv.Expression)
{
return Expression.Invoke(expr, args);
}
return iv;
}
}
public class PartialEvaluator : ExpressionVisitorSql
{
private Func<Expression, bool> m_fnCanBeEvaluated;
private HashSet<Expression> m_candidates; public PartialEvaluator()
: this(CanBeEvaluatedLocally)
{ } public PartialEvaluator(Func<Expression, bool> fnCanBeEvaluated)
{
this.m_fnCanBeEvaluated = fnCanBeEvaluated;
} public Expression Eval(Expression exp)
{
this.m_candidates = new Nominator(this.m_fnCanBeEvaluated).Nominate(exp); return this.Visit(exp);
} protected override Expression Visit(Expression exp)
{
if (exp == null)
{
return null;
} if (this.m_candidates.Contains(exp))
{
return this.Evaluate(exp);
} return base.Visit(exp);
} private Expression Evaluate(Expression e)
{
if (e.NodeType == ExpressionType.Constant)
{
return e;
} LambdaExpression lambda = Expression.Lambda(e);
Delegate fn = lambda.Compile();
return Expression.Constant(fn.DynamicInvoke(null), e.Type);
} private static bool CanBeEvaluatedLocally(Expression exp)
{
return exp.NodeType != ExpressionType.Parameter;
} #region Nominator /// <summary>
/// Performs bottom-up analysis to determine which nodes can possibly
/// be part of an evaluated sub-tree.
/// </summary>
private class Nominator : ExpressionVisitorSql
{
private Func<Expression, bool> m_fnCanBeEvaluated;
private HashSet<Expression> m_candidates;
private bool m_cannotBeEvaluated; internal Nominator(Func<Expression, bool> fnCanBeEvaluated)
{
this.m_fnCanBeEvaluated = fnCanBeEvaluated;
} internal HashSet<Expression> Nominate(Expression expression)
{
this.m_candidates = new HashSet<Expression>();
this.Visit(expression);
return this.m_candidates;
} protected override Expression Visit(Expression expression)
{
if (expression != null)
{
bool saveCannotBeEvaluated = this.m_cannotBeEvaluated;
this.m_cannotBeEvaluated = false; base.Visit(expression); if (!this.m_cannotBeEvaluated)
{
if (this.m_fnCanBeEvaluated(expression))
{
this.m_candidates.Add(expression);
}
else
{
this.m_cannotBeEvaluated = true;
}
} this.m_cannotBeEvaluated |= saveCannotBeEvaluated;
} return expression;
}
} #endregion
}
internal class ConditionBuilder : ExpressionVisitorSql
{
/// <summary>
/// 数据库类型
/// </summary>
private string m_dataBaseType = "";
/// <summary>
/// 字段是否加引号
/// </summary>
private bool m_ifWithQuotationMarks = false; private List<object> m_arguments;
private Stack<string> m_conditionParts; public string Condition { get; private set; } public object[] Arguments { get; private set; } #region 加双引号
/// <summary>
/// 加双引号
/// </summary>
/// <param name="str">字串</param>
/// <returns></returns>
public static string AddQuotationMarks(string str)
{
if (str != null)
{
return "\"" + str.Trim() + "\"";
}
else
{
return str;
}
} #endregion #region 设置是否加双引号
public void SetIfWithQuotationMarks(bool ifwith)
{
m_ifWithQuotationMarks = ifwith;
}
#endregion #region 设置是数据库类型
public void SetDataBaseType(string databaseType)
{
if (!string.IsNullOrEmpty(databaseType))
{
m_dataBaseType = databaseType;
} }
#endregion
public void Build(Expression expression)
{
PartialEvaluator evaluator = new PartialEvaluator();
Expression evaluatedExpression = evaluator.Eval(expression); this.m_arguments = new List<object>();
this.m_conditionParts = new Stack<string>(); this.Visit(evaluatedExpression); this.Arguments = this.m_arguments.ToArray();
this.Condition = this.m_conditionParts.Count > ? this.m_conditionParts.Pop() : null;
} protected override Expression VisitBinary(BinaryExpression b)
{
if (b == null) return b; string opr;
switch (b.NodeType)
{
case ExpressionType.Equal:
opr = "=";
break;
case ExpressionType.NotEqual:
opr = "<>";
break;
case ExpressionType.GreaterThan:
opr = ">";
break;
case ExpressionType.GreaterThanOrEqual:
opr = ">=";
break;
case ExpressionType.LessThan:
opr = "<";
break;
case ExpressionType.LessThanOrEqual:
opr = "<=";
break;
case ExpressionType.AndAlso:
opr = "AND";
break;
case ExpressionType.OrElse:
opr = "OR";
break;
case ExpressionType.Add:
opr = "+";
break;
case ExpressionType.Subtract:
opr = "-";
break;
case ExpressionType.Multiply:
opr = "*";
break;
case ExpressionType.Divide:
opr = "/";
break;
default:
throw new NotSupportedException(b.NodeType + "is not supported.");
} this.Visit(b.Left);
this.Visit(b.Right); string right = this.m_conditionParts.Pop();
string left = this.m_conditionParts.Pop(); string condition = String.Format("({0} {1} {2})", left, opr, right);
this.m_conditionParts.Push(condition); return b;
} protected override Expression VisitConstant(ConstantExpression c)
{
if (c == null) return c; this.m_arguments.Add(c.Value);
this.m_conditionParts.Push(String.Format("{{{0}}}", this.m_arguments.Count - )); return c;
} protected override Expression VisitMemberAccess(MemberExpression m)
{
if (m == null) return m; PropertyInfo propertyInfo = m.Member as PropertyInfo;
if (propertyInfo == null) return m; // this.m_conditionParts.Push(String.Format("(Where.{0})", propertyInfo.Name));
//是否添加引号
if (m_ifWithQuotationMarks)
{
this.m_conditionParts.Push(String.Format(" {0} ", AddQuotationMarks(propertyInfo.Name)));
}
else
{
// this.m_conditionParts.Push(String.Format("[{0}]", propertyInfo.Name));
this.m_conditionParts.Push(String.Format(" {0} ", propertyInfo.Name));
} return m;
} #region 其他
static string BinarExpressionProvider(Expression left, Expression right, ExpressionType type)
{
string sb = "(";
//先处理左边
sb += ExpressionRouter(left); sb += ExpressionTypeCast(type); //再处理右边
string tmpStr = ExpressionRouter(right); if (tmpStr == "null")
{
if (sb.EndsWith(" ="))
sb = sb.Substring(, sb.Length - ) + " is null";
else if (sb.EndsWith("<>"))
sb = sb.Substring(, sb.Length - ) + " is not null";
}
else
sb += tmpStr;
return sb += ")";
} static string ExpressionRouter(Expression exp)
{
string sb = string.Empty;
if (exp is BinaryExpression)
{ BinaryExpression be = ((BinaryExpression)exp);
return BinarExpressionProvider(be.Left, be.Right, be.NodeType);
}
else if (exp is MemberExpression)
{ MemberExpression me = ((MemberExpression)exp);
return me.Member.Name;
}
else if (exp is NewArrayExpression)
{
NewArrayExpression ae = ((NewArrayExpression)exp);
StringBuilder tmpstr = new StringBuilder();
foreach (Expression ex in ae.Expressions)
{
tmpstr.Append(ExpressionRouter(ex));
tmpstr.Append(",");
}
return tmpstr.ToString(, tmpstr.Length - );
}
else if (exp is MethodCallExpression)
{
MethodCallExpression mce = (MethodCallExpression)exp;
if (mce.Method.Name == "Like")
return string.Format("({0} like {1})", ExpressionRouter(mce.Arguments[]), ExpressionRouter(mce.Arguments[]));
else if (mce.Method.Name == "NotLike")
return string.Format("({0} Not like {1})", ExpressionRouter(mce.Arguments[]), ExpressionRouter(mce.Arguments[]));
else if (mce.Method.Name == "In")
return string.Format("{0} In ({1})", ExpressionRouter(mce.Arguments[]), ExpressionRouter(mce.Arguments[]));
else if (mce.Method.Name == "NotIn")
return string.Format("{0} Not In ({1})", ExpressionRouter(mce.Arguments[]), ExpressionRouter(mce.Arguments[]));
else if (mce.Method.Name == "StartWith")
return string.Format("{0} like '{1}%'", ExpressionRouter(mce.Arguments[]), ExpressionRouter(mce.Arguments[]));
}
else if (exp is ConstantExpression)
{
ConstantExpression ce = ((ConstantExpression)exp);
if (ce.Value == null)
return "null";
else if (ce.Value is ValueType)
return ce.Value.ToString();
else if (ce.Value is string || ce.Value is DateTime || ce.Value is char)
{ return string.Format("'{0}'", ce.Value.ToString());
}
}
else if (exp is UnaryExpression)
{
UnaryExpression ue = ((UnaryExpression)exp);
return ExpressionRouter(ue.Operand);
}
return null;
} static string ExpressionTypeCast(ExpressionType type)
{
switch (type)
{
case ExpressionType.And:
case ExpressionType.AndAlso:
return " AND ";
case ExpressionType.Equal:
return " =";
case ExpressionType.GreaterThan:
return " >";
case ExpressionType.GreaterThanOrEqual:
return ">=";
case ExpressionType.LessThan:
return "<";
case ExpressionType.LessThanOrEqual:
return "<=";
case ExpressionType.NotEqual:
return "<>";
case ExpressionType.Or:
case ExpressionType.OrElse:
return " Or ";
case ExpressionType.Add:
case ExpressionType.AddChecked:
return "+";
case ExpressionType.Subtract:
case ExpressionType.SubtractChecked:
return "-";
case ExpressionType.Divide:
return "/";
case ExpressionType.Multiply:
case ExpressionType.MultiplyChecked:
return "*";
default:
return null;
}
}
#endregion /// <summary>
/// ConditionBuilder 并不支持生成Like操作，如 字符串的 StartsWith，Contains，EndsWith 并不能生成这样的SQL： Like ‘xxx%’, Like ‘%xxx%’ , Like ‘%xxx’ . 只要override VisitMethodCall 这个方法即可实现上述功能。
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
protected override Expression VisitMethodCall(MethodCallExpression m)
{
string connectorWords = GetLikeConnectorWords(m_dataBaseType); //获取like链接符 if (m == null) return m;
string format;
switch (m.Method.Name)
{
case "StartsWith":
format = "({0} LIKE ''" + connectorWords + "{1}" + connectorWords + "'%')";
break;
case "Contains":
format = "({0} LIKE '%'" + connectorWords + "{1}" + connectorWords + "'%')";
break;
case "EndsWith":
format = "({0} LIKE '%'" + connectorWords + "{1}" + connectorWords + "'')";
break; case "Equals":
// not in 或者 in 或 not like
format = "({0} ={1} )";
break; default:
throw new NotSupportedException(m.NodeType + " is not supported!");
}
this.Visit(m.Object);
this.Visit(m.Arguments[]);
string right = this.m_conditionParts.Pop();
string left = this.m_conditionParts.Pop(); this.m_conditionParts.Push(String.Format(format, left, right));
return m;
} /// <summary>
/// 获得like语句链接符
/// </summary>
/// <param name="databaseType"></param>
/// <returns></returns>
public static string GetLikeConnectorWords(string databaseType)
{
string result = "+";
switch (databaseType.ToLower())
{
case "postgresql":
case "oracle":
case "mysql":
case "sqlite":
result = "||";
break;
} return result;
} }
}
调用方法
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text; namespace test.DataAccess
{
/// <summary>
/// lambda表达式转为where条件sql
/// </summary>
public class Expression2Sql
{
#region Expression 转成 where
/// <summary>
/// Expression 转成 Where String
/// 支持表达式：==、!= 、Equals、Contains、StartsWith、EndsWith、&&、||
/// 不支持：!（取反）
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="predicate"></param>
/// <param name="databaseType">数据类型（用于字段是否加引号）</param>
/// <returns></returns>
public static string GetWhereByLambda<T>(Expression<Func<T, bool>> predicate, string databaseType = "sqlserver")
{
bool withQuotationMarks = GetWithQuotationMarks(databaseType); ConditionBuilder conditionBuilder = new ConditionBuilder();
//字段是否加引号（PostgreSql,Oracle）
conditionBuilder.SetIfWithQuotationMarks(withQuotationMarks);
conditionBuilder.SetDataBaseType(databaseType);
conditionBuilder.Build(predicate); for (int i = ; i < conditionBuilder.Arguments.Length; i++)
{
object ce = conditionBuilder.Arguments[i];
if (ce == null)
{
//conditionBuilder.Arguments[i] = DBNull.Value;
conditionBuilder.Arguments[i] = "''";
}
else if (ce is string || ce is char)
{
if (ce.ToString().ToLower().Trim().IndexOf(@"in(") == ||
ce.ToString().ToLower().Trim().IndexOf(@"not in(") == ||
ce.ToString().ToLower().Trim().IndexOf(@" like '") == ||
ce.ToString().ToLower().Trim().IndexOf(@"not like") == )
{
conditionBuilder.Arguments[i] = string.Format(" {0} ", ce.ToString());
}
else
{
conditionBuilder.Arguments[i] = string.Format("'{0}'", ce.ToString());
}
}
else if (ce is DateTime)
{
conditionBuilder.Arguments[i] = string.Format("'{0}'", ce.ToString());
}
else if (ce is int || ce is long || ce is short || ce is decimal || ce is double || ce is float || ce is bool || ce is byte || ce is sbyte)
{
conditionBuilder.Arguments[i] = ce.ToString();
}
else if (ce is ValueType)
{
conditionBuilder.Arguments[i] = ce.ToString();
}
else
{
conditionBuilder.Arguments[i] = string.Format("'{0}'", ce.ToString());
} } return string.Format(conditionBuilder.Condition, conditionBuilder.Arguments);
} /// <summary>
/// 获取是否字段加双引号
/// </summary>
/// <param name="databaseType"></param>
/// <returns></returns>
public static bool GetWithQuotationMarks(string databaseType)
{
bool result = false;
switch (databaseType.ToLower())
{
case "postgresql":
case "oracle":
result = true;
break;
} return result;
}
#endregion
}
}
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