Merge pull request #306 from mk3008/293-request-parsing-mysql-system-…

…variables

Supports parsing of MySQL system variables

src/Carbunql/Analysis/LexReader.cs

@@ -120,6 +120,17 @@ public string ReadLex(bool skipSpace = true)
 			return sb.ToString();
 		}
 
+		// ex. @@ (MySQL system variable)
+		if (fc == '@')
+		{
+			var isFirst = true;
+			foreach (var item in ReadChars(x => isFirst && x == '@'))
+			{
+				sb.Append(item);
+				isFirst = false;
+			}
+		}
+
 		// ex. . or , or (
 		if (SingleSymbols.Contains(fc)) return sb.ToString();
 
@@ -144,7 +155,7 @@ public string ReadLex(bool skipSpace = true)
 		// ex. 123.45
 		if (fc.IsInteger())
 		{
-			foreach (var item in ReadChars((x) => "0123456789.".ToArray().Contains(x)))
+			foreach (var item in ReadChars(x => "0123456789.".ToArray().Contains(x)))
 			{
 				sb.Append(item);
 			}

src/Carbunql/Analysis/Parser/ParameterValueParser.cs

@@ -7,6 +7,7 @@ public static class ParameterValueParser
 {
 	public static bool IsParameterValue(string text)
 	{
+		if (text.StartsWith("@@")) return false;
 		return text.StartsWith(new string[] { ":", "@", "?" });
 	}
 

test/Carbunql.Analysis.Test/ValueParseTest.cs

@@ -667,4 +667,19 @@ public void PostgresArray()
 		var lst = v.GetTokens().ToList();
 		Assert.Equal(6, lst.Count);
 	}
+
+	[Fact]
+	public void MySqlSystemVariable()
+	{
+		var text = "@@session.time_zone";
+		var v = ValueParser.Parse(text);
+		Monitor.Log(v);
+
+		var lst = v.GetTokens().ToList();
+		Assert.Equal(3, lst.Count);
+
+		var expect = "@@session.time_zone";
+
+		Assert.Equal(expect, v.ToText());
+	}
 }