Fix evaluation of conditions with constants (WIP)

src/main/java/uk/ac/ed/pguaglia/real/lang/Equality.java

@@ -54,9 +54,9 @@ public class Equality extends Condition {
 	@Override
 	public String toSQL() {
 		String left = this.left.isAttribute() ?
-				Database.encode(this.left.getValue()) : "'" + this.left.getValue() + "'";
+				Database.encode(this.left.getValue()) : this.left.getValue();
 		String right = this.right.isAttribute() ?
-				Database.encode(this.right.getValue()) : "'" + this.right.getValue() + "'";
+				Database.encode(this.right.getValue()) : this.right.getValue();
 		return  left + " = " + right;
 	}
 }

src/main/java/uk/ac/ed/pguaglia/real/lang/LessThan.java

@@ -55,10 +55,19 @@ public class LessThan extends Condition {
 
 	@Override
 	public String toSQL() {
-		String left = this.left.isAttribute() ?
-				Database.encode(this.left.getValue()) : "'" + this.left.getValue() + "'";
-		String right = this.right.isAttribute() ?
-				Database.encode(this.right.getValue()) : "'" + this.right.getValue() + "'";
+		// This is a hack TODO: introduce types?
+		String left = this.left.getValue();
+		if (this.left.isAttribute()) {
+			left = Database.encode(left);			
+		} else if (left.startsWith("'") == false) {
+			left = "CAST(" + left + " AS int)";
+		}
+		String right = this.right.getValue();
+		if (this.right.isAttribute()) {
+			right = Database.encode(right);			
+		} else if (right.startsWith("'") == false) {
+			right = "CAST( " + right + " AS int)";
+		}
 		return  left + " < " + right;
 	}
 }