/// <summary>
/// Visits a MatchCase builder.
/// </summary>
/// <param name="item">The item to visit.</param>
protected internal virtual void VisitMatchCase(MatchCase item)
{
}
/// <summary>
/// Generates the text for a MatchCase builder.
/// </summary>
/// <param name="item">The MatchCase builder to generate the text for.</param>
protected internal override void VisitMatchCase(MatchCase item)
{
if (!item.Branches.Any())
{
throw new SQLGenerationException(Resources.EmptyCaseExpression);
}
writer.Write("CASE ");
item.Item.Accept(forSubCommand());
writer.Write(" ");
foreach (MatchCaseBranch branch in item.Branches)
{
writer.Write("WHEN ");
branch.Option.Accept(forSubCommand());
writer.Write(" THEN ");
branch.Value.Accept(forSubCommand());
writer.Write(" ");
}
if (item.Default != null)
{
writer.Write("ELSE ");
item.Default.Accept(forSubCommand());
writer.Write(" ");
}
writer.Write("END");
}
private void buildMatchList(MatchResult result, MatchCase options)
{
MatchResult match = result.Matches[SqlGrammar.MatchList.Match];
buildMatch(match, options);
MatchResult matchListPrime = result.Matches[SqlGrammar.MatchList.MatchListPrime];
buildMatchListPrime(matchListPrime, options);
}
private void buildMatchListPrime(MatchResult result, MatchCase options)
{
MatchResult matchResult = result.Matches[SqlGrammar.MatchListPrime.Match.Name];
if (matchResult.IsMatch)
{
MatchResult firstResult = matchResult.Matches[SqlGrammar.MatchListPrime.Match.First];
buildMatch(firstResult, options);
MatchResult remainingResult = matchResult.Matches[SqlGrammar.MatchListPrime.Match.Remaining];
buildMatchListPrime(remainingResult, options);
return;
}
MatchResult elseResult = result.Matches[SqlGrammar.MatchListPrime.Else.Name];
if (elseResult.IsMatch)
{
MatchResult valueResult = elseResult.Matches[SqlGrammar.MatchListPrime.Else.Value];
options.Default = (IProjectionItem)buildArithmeticItem(valueResult);
return;
}
MatchResult emptyResult = result.Matches[SqlGrammar.MatchListPrime.Empty];
if (emptyResult.IsMatch)
{
return;
}
throw new InvalidOperationException();
}
private MatchCase buildMatchCase(MatchResult result)
{
MatchResult expressionResult = result.Matches[SqlGrammar.MatchCase.Expression];
IProjectionItem expression = (IProjectionItem)buildArithmeticItem(expressionResult);
MatchCase options = new MatchCase(expression);
MatchResult matchListResult = result.Matches[SqlGrammar.MatchCase.MatchList];
buildMatchList(matchListResult, options);
return options;
}
private void buildMatch(MatchResult result, MatchCase options)
{
MatchResult expressionResult = result.Matches[SqlGrammar.Match.Expression];
IProjectionItem expression = (IProjectionItem)buildArithmeticItem(expressionResult);
MatchResult valueResult = result.Matches[SqlGrammar.Match.Value];
IProjectionItem value = (IProjectionItem)buildArithmeticItem(valueResult);
options.AddBranch(expression, value);
}
public void TestSelect_MatchCase_MultipleCases()
{
SelectBuilder builder = new SelectBuilder();
AliasedSource source = builder.AddTable(new Table("Table"));
Column column = source.Column("Column");
MatchCase options = new MatchCase(column);
options.AddBranch(new NumericLiteral(0), new StringLiteral("Sunday"));
options.AddBranch(new NumericLiteral(1), new StringLiteral("Monday"));
options.AddBranch(new NumericLiteral(2), new StringLiteral("Tuesday"));
options.AddBranch(new NumericLiteral(3), new StringLiteral("Wednesday"));
options.AddBranch(new NumericLiteral(4), new StringLiteral("Thursday"));
options.AddBranch(new NumericLiteral(5), new StringLiteral("Friday"));
options.AddBranch(new NumericLiteral(6), new StringLiteral("Saturday"));
builder.AddProjection(options);
Formatter formatter = new Formatter();
string actual = formatter.GetCommandText(builder);
string expected = "SELECT CASE Table.Column WHEN 0 THEN 'Sunday' WHEN 1 THEN 'Monday' WHEN 2 THEN 'Tuesday' WHEN 3 THEN 'Wednesday' WHEN 4 THEN 'Thursday' WHEN 5 THEN 'Friday' WHEN 6 THEN 'Saturday' END FROM Table";
Assert.AreEqual(expected, actual, "The wrong SQL was generated.");
}
public void TestSelect_MatchCase_Else()
{
SelectBuilder builder = new SelectBuilder();
AliasedSource source = builder.AddTable(new Table("Table"));
Column column = source.Column("Column");
MatchCase options = new MatchCase(column);
options.AddBranch(new StringLiteral("Admin"), new StringLiteral("Administrator"));
options.Default = new StringLiteral("User");
builder.AddProjection(options);
Formatter formatter = new Formatter();
string actual = formatter.GetCommandText(builder);
string expected = "SELECT CASE Table.Column WHEN 'Admin' THEN 'Administrator' ELSE 'User' END FROM Table";
Assert.AreEqual(expected, actual, "The wrong SQL was generated.");
}
/// <summary>
/// Visits a MatchCase builder.
/// </summary>
/// <param name="item">The item to visit.</param>
protected internal virtual void VisitMatchCase(MatchCase item)
{
}