public void SelectClause_StopAtFrom()
{
using (StringReader reader = new StringReader(@"select a from b;"))
using (TSQLTokenizer tokenizer = new TSQLTokenizer(reader))
{
Assert.IsTrue(tokenizer.Read());
TSQLSelectClause select = new TSQLSelectClauseParser().Parse(tokenizer);
Assert.AreEqual(2, select.Tokens.Count);
Assert.AreEqual(TSQLKeywords.FROM, tokenizer.Current.AsKeyword.Keyword);
}
}
public TSQLSelectStatement Parse(TSQLTokenizer tokenizer)
{
TSQLSelectStatement select = new TSQLSelectStatement();
// should whitespace be excluded from statement parsing logic?
// should I differentiate keywords that start commands?
// correlated subqueries
// scalar function calls
// SELECT clause
TSQLSelectClause selectClause = new TSQLSelectClauseParser().Parse(tokenizer);
select.Select = selectClause;
select.Tokens.AddRange(selectClause.Tokens);
if (tokenizer.Current.IsKeyword(TSQLKeywords.INTO))
{
TSQLIntoClause intoClause = new TSQLIntoClauseParser().Parse(tokenizer);
select.Into = intoClause;
select.Tokens.AddRange(intoClause.Tokens);
}
if (tokenizer.Current.IsKeyword(TSQLKeywords.FROM))
{
TSQLFromClause fromClause = new TSQLFromClauseParser().Parse(tokenizer);
select.From = fromClause;
select.Tokens.AddRange(fromClause.Tokens);
}
if (tokenizer.Current.IsKeyword(TSQLKeywords.WHERE))
{
TSQLWhereClause whereClause = new TSQLWhereClauseParser().Parse(tokenizer);
select.Where = whereClause;
select.Tokens.AddRange(whereClause.Tokens);
}
if (tokenizer.Current.IsKeyword(TSQLKeywords.GROUP))
{
TSQLGroupByClause groupByClause = new TSQLGroupByClauseParser().Parse(tokenizer);
select.GroupBy = groupByClause;
select.Tokens.AddRange(groupByClause.Tokens);
}
if (tokenizer.Current.IsKeyword(TSQLKeywords.HAVING))
{
TSQLHavingClause havingClause = new TSQLHavingClauseParser().Parse(tokenizer);
select.Having = havingClause;
select.Tokens.AddRange(havingClause.Tokens);
}
if (tokenizer.Current.IsKeyword(TSQLKeywords.ORDER))
{
TSQLOrderByClause orderByClause = new TSQLOrderByClauseParser().Parse(tokenizer);
select.OrderBy = orderByClause;
select.Tokens.AddRange(orderByClause.Tokens);
}
if (tokenizer.Current.IsCharacter(TSQLCharacters.Semicolon))
{
select.Tokens.Add(tokenizer.Current);
}
return select;
}