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Finished most work to parse column expressions. Still need to fix sub…
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…selects and window functions. #6
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@bruce-dunwiddie
bruce-dunwiddie committed Nov 27, 2020
1 parent 5c8b038 commit 0b95847
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Showing 16 changed files with 241 additions and 154 deletions.
113 changes: 59 additions & 54 deletions TSQL_Parser/TSQL_Parser/Clauses/Parsers/TSQLSelectClauseParser.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -23,65 +23,70 @@ public TSQLSelectClause Parse(ITSQLTokenizer tokenizer)

select.Tokens.Add(tokenizer.Current);

// need to part TOP, DISTINCT, etc here
tokenizer.MoveNext();

TSQLSubqueryHelper.ReadUntilStop(
tokenizer,
select,
new List<TSQLFutureKeywords>() { },
new List<TSQLKeywords>() {
TSQLKeywords.INTO,
TSQLKeywords.FROM,
TSQLKeywords.WHERE,
TSQLKeywords.GROUP,
TSQLKeywords.HAVING,
TSQLKeywords.ORDER,
TSQLKeywords.UNION,
TSQLKeywords.EXCEPT,
TSQLKeywords.INTERSECT,
TSQLKeywords.FOR,
TSQLKeywords.OPTION
},
lookForStatementStarts: true);
while (
tokenizer.Current != null &&
!tokenizer.Current.IsCharacter(TSQLCharacters.Semicolon) &&
!tokenizer.Current.IsCharacter(TSQLCharacters.CloseParentheses) &&
!(
tokenizer.Current.Type == TSQLTokenType.Keyword &&
(
tokenizer.Current.AsKeyword.Keyword.In(
TSQLKeywords.INTO,
TSQLKeywords.FROM,
TSQLKeywords.WHERE,
TSQLKeywords.GROUP,
TSQLKeywords.HAVING,
TSQLKeywords.ORDER,
TSQLKeywords.UNION,
TSQLKeywords.EXCEPT,
TSQLKeywords.INTERSECT,
TSQLKeywords.FOR,
TSQLKeywords.OPTION) ||
tokenizer.Current.AsKeyword.Keyword.IsStatementStart()
)
))
{
if (tokenizer.Current.IsWhitespace() ||
tokenizer.Current.IsComment() ||
tokenizer.Current.IsCharacter(TSQLCharacters.Comma))
{
select.Tokens.Add(tokenizer.Current);

tokenizer.MoveNext();
}
else if (tokenizer.Current.IsKeyword(TSQLKeywords.DISTINCT))
{
select.Tokens.Add(tokenizer.Current);

tokenizer.MoveNext();
}
else if (tokenizer.Current.IsKeyword(TSQLKeywords.TOP))
{
select.Tokens.Add(tokenizer.Current);

tokenizer.MoveNext();

// TODO: switch logic to use below once expression parsers are fully functional
//if (tokenizer.MoveNext())
//{
// if (tokenizer.Current.Type == TSQLTokenType.NumericLiteral)
// {
// select.Tokens.Add(tokenizer.Current);
// }

//while (tokenizer.MoveNext() &&
// !tokenizer.Current.IsCharacter(TSQLCharacters.Semicolon) &&
// !(
// tokenizer.Current.Type == TSQLTokenType.Keyword &&
// (
// tokenizer.Current.AsKeyword.Keyword.In(
// TSQLKeywords.INTO,
// TSQLKeywords.FROM,
// TSQLKeywords.WHERE,
// TSQLKeywords.GROUP,
// TSQLKeywords.HAVING,
// TSQLKeywords.ORDER,
// TSQLKeywords.UNION,
// TSQLKeywords.EXCEPT,
// TSQLKeywords.INTERSECT,
// TSQLKeywords.FOR,
// TSQLKeywords.OPTION) ||
// tokenizer.Current.AsKeyword.Keyword.IsStatementStart()
// )
// ))
//{
// if (tokenizer.Current.IsWhitespace() ||
// tokenizer.Current.IsComment() ||
// tokenizer.Current.IsCharacter(TSQLCharacters.Comma))
// {
// select.Tokens.Add(tokenizer.Current);
// }
// else
// {
// TSQLSelectColumn column = new TSQLSelectColumnParser().Parse(tokenizer);
// // TODO: how to handle TOP N vs TOP(N)
//}
}
else
{
TSQLSelectColumn column = new TSQLSelectColumnParser().Parse(tokenizer);

// select.Tokens.AddRange(column.Tokens);
select.Tokens.AddRange(column.Tokens);

// select.Columns.Add(column);
// }
//};
select.Columns.Add(column);
}
};

return select;
}
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26 changes: 20 additions & 6 deletions TSQL_Parser/TSQL_Parser/Elements/Parsers/TSQLSelectColumnParser.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -22,20 +22,34 @@ public TSQLSelectColumn Parse(ITSQLTokenizer tokenizer)

column.Tokens.AddRange(columnExpression.Tokens);

if (tokenizer.Current.IsKeyword(TSQLKeywords.AS))
while (
tokenizer.Current != null &&
(
tokenizer.Current.IsWhitespace() ||
tokenizer.Current.IsComment())
)
{
column.Tokens.Add(tokenizer.Current);

tokenizer.MoveNext();
}

while (
tokenizer.Current.IsWhitespace() ||
tokenizer.Current.IsComment())
if (
tokenizer.Current != null &&
tokenizer.Current.IsKeyword(TSQLKeywords.AS))
{
column.Tokens.Add(tokenizer.Current);

tokenizer.MoveNext();

while (
tokenizer.Current.IsWhitespace() ||
tokenizer.Current.IsComment())
{
column.Tokens.Add(tokenizer.Current);

tokenizer.MoveNext();
}
}

if (tokenizer.Current != null &&
Expand All @@ -46,9 +60,9 @@ public TSQLSelectColumn Parse(ITSQLTokenizer tokenizer)
column.Tokens.Add(tokenizer.Current);

column.Alias = tokenizer.Current;
}

tokenizer.MoveNext();
tokenizer.MoveNext();
}

return column;
}
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2 changes: 2 additions & 0 deletions TSQL_Parser/TSQL_Parser/Expressions/Parsers/TSQLCaseExpressionParser.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -37,6 +37,8 @@ public TSQLCaseExpression Parse(ITSQLTokenizer tokenizer)
// the other parsers
caseExpression.Tokens.Add(tokenizer.Current);

tokenizer.MoveNext();

return caseExpression;
}
}
Expand Down
130 changes: 128 additions & 2 deletions TSQL_Parser/TSQL_Parser/Expressions/Parsers/TSQLExpressionFactory.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -80,6 +80,8 @@ private TSQLExpression ParseNext(
group.Tokens.Add(tokenizer.Current);
}

// TODO: handle subselect starting with SELECT vs an expression

group.InnerExpression = Parse(tokenizer);
group.Tokens.AddRange(group.InnerExpression.Tokens);

Expand Down Expand Up @@ -166,7 +168,41 @@ private TSQLExpression ParseNext(
else if (tokenizer.Current.Type.In(
TSQLTokenType.SystemIdentifier))
{
return new TSQLFunctionExpression();
TSQLFunctionExpression function = new TSQLFunctionExpression();

function.Name = tokenizer.Current.Text;

function.Tokens.Add(tokenizer.Current);

if (tokenizer.MoveNext() &&
tokenizer.Current.IsCharacter(TSQLCharacters.OpenParentheses))
{
function.Tokens.Add(tokenizer.Current);

TSQLArgumentList arguments = new TSQLArgumentListParser().Parse(
tokenizer);

function.Tokens.AddRange(arguments.Tokens);

function.Arguments = arguments;

if (tokenizer.Current.IsCharacter(TSQLCharacters.CloseParentheses))
{
function.Tokens.Add(tokenizer.Current);
}

while (
tokenizer.MoveNext() &&
(
tokenizer.Current.IsWhitespace() ||
tokenizer.Current.IsComment())
)
{
function.Tokens.Add(tokenizer.Current);
}
}

return function;
}
else if (tokenizer.Current.Type.In(
TSQLTokenType.Identifier))
Expand All @@ -184,6 +220,8 @@ private TSQLExpression ParseNext(

// alias would be any tokens prior to last period, removing whitespace, concatenated together as string

// TODO: handle window functions with multiple parts

List<TSQLToken> tokens = new List<TSQLToken>();

tokens.Add(tokenizer.Current);
Expand All @@ -203,10 +241,98 @@ private TSQLExpression ParseNext(
function.Tokens.AddRange(arguments.Tokens);

function.Arguments = arguments;

if (tokenizer.Current.IsCharacter(TSQLCharacters.CloseParentheses))
{
function.Tokens.Add(tokenizer.Current);
}

function.Name =
String.Join(
"",
tokens
.Where(t => !t.IsComment() && !t.IsWhitespace())
.Select(t => t.Text));

while (
tokenizer.MoveNext() &&
(
tokenizer.Current.IsWhitespace() ||
tokenizer.Current.IsComment())
)
{
function.Tokens.Add(tokenizer.Current);
}

return function;
}
else if (tokenizer.Current.Text == "*")
{
// e.g. p.*

TSQLMulticolumnExpression multi = new TSQLMulticolumnExpression();

multi.Tokens.AddRange(tokens);

multi.Tokens.Add(tokenizer.Current);

string alias =
String.Join(
"",
tokens
.Where(t => !t.IsComment() && !t.IsWhitespace())
.Select(t => t.Text));

// trim off the last period
multi.TableAlias = alias.Substring(0, alias.Length - 1);

while (
tokenizer.MoveNext() &&
(
tokenizer.Current.IsWhitespace() ||
tokenizer.Current.IsComment())
)
{
multi.Tokens.Add(tokenizer.Current);
}

return multi;
}
else if (
tokenizer.Current.IsCharacter(TSQLCharacters.Comma) ||
tokenizer.Current.IsCharacter(TSQLCharacters.CloseParentheses) ||
tokenizer.Current.Type == TSQLTokenType.Keyword)
{
TSQLColumnExpression column = new TSQLColumnExpression();

column.Tokens.AddRange(tokens);

string alias =
String.Join(
"",
tokens
.Where(t => !t.IsComment() && !t.IsWhitespace())
.Select(t => t.Text));

// trim off the last period
column.TableAlias = alias.Substring(0, alias.Length - 1);

tokens.Reverse();

column.Column = tokens
.Where(t => !t.IsComment() && !t.IsWhitespace())
.Select(t => t.Text)
.First();

return column;
}
else
{
tokens.Add(tokenizer.Current);
}
}

return new TSQLFunctionExpression();
return null;
}
else
{
Expand Down
8 changes: 1 addition & 7 deletions TSQL_Parser/TSQL_Parser/Expressions/TSQLMulticolumnExpression.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -16,12 +16,6 @@ public override TSQLExpressionType Type
}
}

public string TableAlias
{
get
{
return null;
}
}
public string TableAlias { get; internal set; }
}
}
7 changes: 0 additions & 7 deletions TSQL_Parser/TSQL_Parser/Statements/Parsers/TSQLDeleteStatementParser.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -71,13 +71,6 @@ public TSQLDeleteStatement Parse()

Statement.Tokens.AddRange(optionClause.Tokens);
}

if (
Tokenizer.Current?.AsKeyword != null &&
Tokenizer.Current.AsKeyword.Keyword.IsStatementStart())
{
Tokenizer.Putback();
}

return Statement;
}
Expand Down
7 changes: 0 additions & 7 deletions TSQL_Parser/TSQL_Parser/Statements/Parsers/TSQLExecuteStatementParser.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,13 +31,6 @@ public TSQLExecuteStatement Parse()
new List<TSQLKeywords>() { },
lookForStatementStarts: true);

if (
Tokenizer.Current?.AsKeyword != null &&
Tokenizer.Current.AsKeyword.Keyword.IsStatementStart())
{
Tokenizer.Putback();
}

return Statement;
}

Expand Down
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