/// <summary>
/// 由对象查询语句解析为Sql语句
/// </summary>
/// <param name="oql"></param>
/// <param name="sql"></param>
/// <param name="parameters"></param>
public static string ParseSql(string oql,IMap map)
{
if(oql==string.Empty)
return string.Empty;
SyntaxNode syntaxNode=new SyntaxNode();
syntaxNode.Sentence = oql;
if (syntaxNode.Map == null)
syntaxNode.Map = map;
string sql = syntaxNode.GetSql();
return sql;
}
/// <summary>
/// 在碰到“'”后，取出整个字符串的内容
/// </summary>
/// <param name="charArray">字符数组</param>
/// <param name="index">当前字符位置</param>
private void ParseInQuotation(ref Char[] charArray, ref int index)
{
string inQuotationString = "'";
index++;
//遍历当前字符串到倒数第二个字符
for (; index < charArray.Length - 1; index++)
{
char c = charArray[index];
if (c == '\'')
{
if (charArray[index + 1] == '\'') //如果“'”后面的还是“'”，SQL解析为一个“'”
{
inQuotationString += "''";
index++; //跳过第二个“'”
}
else //出现了另一个“'”号，记录整个字符串
{
inQuotationString += "'";
SyntaxNode node = new SyntaxNode();
node.ParentNode = this;
node.SentenceType = SentenceType.String;
node.sentence = inQuotationString;
nodes.Add(node);
return;
}
}
else
{
inQuotationString += c.ToString();
}
}
//处理最后一个字符
char lastChar = charArray[charArray.Length - 1];
if (lastChar == '\'')
{
SyntaxNode node = new SyntaxNode();
node.ParentNode = this;
node.SentenceType = SentenceType.String;
node.sentence = inQuotationString+"'";
nodes.Add(node);
}
else
{
throw new Exception("缺少“'”");
}
}
/// <summary>
/// 在碰到“(”后，取出与之对应的“)”之间的内容
/// </summary>
/// <param name="charArray">字符数组</param>
/// <param name="index">当前字符位置</param>
private void ParseInBracket(ref Char[] charArray, ref int index)
{
int bracketDepth=1;//括号深度，“（”加1，“）”减1
bool inQuotation = false;//是否在引号内
string inBracketString=string.Empty;
index++;
//遍历当前字符串到倒数第二个字符
for (; index < charArray.Length - 1; index++)
{
char c = charArray[index];
if (inQuotation) //如果在引号内，后面有两个连续的“'”则当成普通字符，一个“'”则结束字符串
{
if (c == '\'') //出现一个引号后再出现了另一个引号
{
if (charArray[index + 1] == '\'')//如果“'”后面的还是“'”，SQL解析为一个“'”
{
inBracketString += "''";
index++; //跳过第二个“'”
}
else
{
inQuotation = false;
inBracketString += "'";
}
}
else //除“'”号之外的其它字符则加到字符串中
{
inBracketString += c.ToString();
}
}
else //不在引号内
{
if (c == '\'') //出现了第一个引号，设置inQuotation为true
{
inQuotation = true;
inBracketString += "'";
}
else if (c == '(') //出现了“(”则括号计数加1
{
inBracketString += "(";
bracketDepth++;
}
else if (c == ')') //出现了“)”则括号计数减1，如果计数为0则表示此次整个括号的内容结束
{
bracketDepth--;
if (bracketDepth == 0)
{
SyntaxNode node = new SyntaxNode();
node.SentenceType = SentenceType.InBracket;
node.Sentence = inBracketString;
node.parentNode = this;
nodes.Add(node);
return;
}
else
{
inBracketString += ")";
}
}
else
{
inBracketString += c.ToString();
}
}
}
//处理最后一个字符
char lastChar = charArray[charArray.Length - 1];
if (lastChar == ')' && bracketDepth==1)
{
SyntaxNode node = new SyntaxNode();
node.parentNode = this;
node.SentenceType = SentenceType.InBracket;
node.Sentence = inBracketString;
nodes.Add(node);
}
else
{
throw new Exception("缺少“)”");
}
}
/// <summary>
/// 解析整条语句，生成树型结构
/// </summary>
public void Parse()
{
string s = string.Empty;
Char[] charArray = sentence.ToCharArray();
for (int i = 0; i < charArray.Length; i++)
{
char c=charArray[i];
if (c == '\'') //如果碰见一个“'”，调用ParseInQuotation记录从该处开始其后的字符串
{
if (s != string.Empty)
{
throw new Exception("“'”附近有语法错误");
}
ParseInQuotation(ref charArray, ref i);
}
else if (c == '(') //如果碰见一个“（”，调用ParseInBracket记录从该处开始到与之对应的“)”之间的内容
{
string funName = string.Empty;
if (s != string.Empty)
{
SyntaxNode node = new SyntaxNode();
node.ParentNode = this;
node.sentence = s;
node.SentenceType = SentenceType.Function;
this.nodes.Add(node);
funName = s.ToLower();
s = string.Empty;
}
ParseInBracket(ref charArray, ref i);
if (funKeywords.Contains(funName) && this.nodes[this.nodes.Count - 1].nodes.Count > 0)
this.nodes[this.nodes.Count - 1].nodes[0].SentenceType = SentenceType.Keyword;
}
else if (c == ' ') //如果碰见一个空格，记录空格前的内容
{
if (s != string.Empty)
{
SyntaxNode node = new SyntaxNode();
node.ParentNode = this;
if (nodes.Count > 0 && nodes[nodes.Count - 1].sentenceType == SentenceType.From)
{
node.sentenceType = SentenceType.Entity;
EntityInfo entityInfo = EntityMap.GetEntityInfo(GetName(s));
if (entityInfo == null)
throw new Exception("from后有语法错误，使用了一个不存在的实体名");
this.map = entityInfo.PropertyMap;
}
else
node.SentenceType = GetSentenceType(s);
node.sentence = GetName(s) + " ";
this.nodes.Add(node);
s = string.Empty;
}
}
else if (c == '+' || c == '-' || c == '*' || c == '/' || c == '=' || c == '!' || c == '<' || c == '>' || c == ',')//如果碰见一个符号，记录符号前的内容及符号本身
{
if (s != string.Empty)
{
SyntaxNode node = new SyntaxNode();
node.ParentNode = this;
node.SentenceType = GetSentenceType(s);
node.sentence = s;
this.nodes.Add(node);
}
SyntaxNode operatorNode = new SyntaxNode();
operatorNode.ParentNode = this;
operatorNode.SentenceType = SentenceType.Symbol;
operatorNode.sentence = c.ToString();
this.nodes.Add(operatorNode);
s = string.Empty;
}
else
{
s += c.ToString();
}
}
//记录最后的内容
if (s != string.Empty)
{
SyntaxNode node = new SyntaxNode();
node.parentNode = this;
if (nodes.Count > 0 && nodes[nodes.Count - 1].sentenceType == SentenceType.From)
{
node.sentenceType = SentenceType.Entity;
EntityInfo entityInfo = EntityMap.GetEntityInfo(GetName(s));
if (entityInfo == null)
throw new Exception("from后有语法错误，使用了一个不存在的实体名");
this.map = entityInfo.PropertyMap;
}
else
node.SentenceType = GetSentenceType(s);
node.sentence = GetName(s);
this.nodes.Add(node);
}
}
