//INTEGER | FLOAT | BOOLEAN | STRING | NAME | PARAM;
private Expression ParseLiteral(RQ q)
{
if (q.IsNext(tokens["name"]))
{
RowValueExpression rv = new RowValueExpression();
rv.row = q.Pop().value;
return(rv);
}
if (q.IsNext(tokens["int"]) || q.IsNext(tokens["float"]) || q.IsNext(tokens["bool"]))
{
ValueExpression v = new ValueExpression();
v.value = q.Pop().value;
return(v);
}
if (q.IsNext(tokens["param"]))
{
ValueExpression v = new ValueExpression();
v.value = q.Peek().value;
v.parameterId = int.Parse(v.value.Remove(0, 1));
return(v);
}
if (q.IsNext(tokens["string"]))
{
ValueExpression v = new ValueExpression();
v.value = q.Peek().value.Remove(0, 1);
v.value = v.value.Remove(v.value.Length - 1);
q.Pop();
return(v);
}
return(null);
}
//'UPDATE' NAME 'SET' (NAME '=' expression) (',' NAME '=' expression)* ('WHERE' expression)?
private Query ParseUpdate(RQ q)
{
if (!q.IsNext(tokens["update"]))
{
return(null);
}
q.Pop();
TableSource s = ParseSource(q);
if (!q.IsNext(tokens["set"]))
{
return(null);
}
q.Pop();
List <string> fields = new List <string>();
List <Expression> values = new List <Expression>();
while (true)
{
if (!q.IsNext(tokens["name"]))
{
break;
}
string field = q.Pop().value;
if (!q.IsNext(tokens["compare"]))
{
break;
}
string op = q.Peek().value;
if (op != "=")
{
break;
}
q.Pop();
Expression e2 = ParseExpression(q);
fields.Add(field);
values.Add(e2);
if (!q.IsNext(tokens["comma"]))
{
break;
}
}
if (!q.IsNext(tokens["where"]))
{
return(null);
}
q.Pop();
Expression e = ParseExpression(q);
if (e == null)
{
e = new TrueExpression();
}
UpdateQuery u = new UpdateQuery();
u.table = s;
u.fields = fields.ToArray();
u.values = values.ToArray();
u.exp = e;
return(u);
}