public void ShouldResolveMaxFunction()
{
//Arrange
string rawTsql = "MAX(CAST(timestamp as bigint))";
IExpressionResolver resolver = new TsqlFunctionResolver();
int fileIndex = 0;
CompilerContext context = new CompilerContext("xUnit", "irrelevant", "irrelevant", true);
ReadOnlySpan <TSQLToken> tokens = TSQLTokenizer.ParseTokens(rawTsql).ToArray();
//Act
Expression expression = resolver.Resolve(tokens, ref fileIndex, context);
//Assert
Assert.Equal(tokens.Length, fileIndex);
}
public void ShouldResolveHashBytesFunction()
{
//Arrange
string rawTsql = "hashbytes ('sha1337', isNull(cast(somecolumn_01 as varchar), '') " +
"+ isNull(cast(cast(somecolumn_02 as date) as varchar), '')" +
"+ isNull(cast(somecolumn_04 collate Latin1_General_CI_AS as NVARCHAR(64)), ''))";
IExpressionResolver resolver = new TsqlFunctionResolver();
int fileIndex = 0;
CompilerContext context = new CompilerContext("xUnit", "irrelevant", "irrelevant", true);
ReadOnlySpan <TSQLToken> tokens = TSQLTokenizer.ParseTokens(rawTsql).ToArray();
//Act
Expression expression = resolver.Resolve(tokens, ref fileIndex, context);
//Assert
Assert.Equal(tokens.Length, fileIndex);
}
/// <summary>
/// Resolves a database object and adds it to the current context as well
/// as to the landscape
/// </summary>
/// <param name="asTargetTable">If the database object is expected to be a target table standart database and server are
/// not added. We also may expect an opening bracket directly after the identifier which is the then not count as a function start</param>
/// <returns>The database object</returns>
internal static DatabaseObject ResolveDatabaseObject(ReadOnlySpan <TSQLToken> tokens, ref int fileIndex, CompilerContext context, bool asTargetTable = false)
{
DatabaseObject dbo;
if (tokens[fileIndex].Text.Equals("("))
{
fileIndex++; //skip '('
dbo = ResolveDatabaseObject(tokens, ref fileIndex, context, asTargetTable);
fileIndex++; //skip ')'
}
else if (tokens[fileIndex].Text.ToLower().Equals("select"))
{
var resolver = new SelectStatementResolver();
var statement = resolver.Resolve(tokens, ref fileIndex, context);
dbo = new DatabaseObject(DatabaseObjectType.SELECTION);
dbo.Expressions.AddRange(statement.ChildExpressions);
}
else if (tokens[fileIndex].Type.Equals(TSQLTokenType.Identifier))
{
int positionBeforeNotationResolution = fileIndex;
string notation = ResolveDatabaseObjectIdentifier(tokens, ref fileIndex);
if (tokens.Length > fileIndex && tokens[fileIndex].Text.Equals("(") && !asTargetTable)
{
//In this section we asssume that the database object is returned by a function
fileIndex = positionBeforeNotationResolution;
var functionResolver = new TsqlFunctionResolver();
var function = functionResolver.Resolve(tokens, ref fileIndex, context);
dbo = new DatabaseObject(DatabaseObjectType.SELECTION);
dbo.Expressions.Add(function);
}
else
{
dbo = new DatabaseObject(notation, context, DatabaseObjectType.REAL, !asTargetTable);
}
}
else if (tokens[fileIndex].Type.Equals(TSQLTokenType.Variable))
{
dbo = new DatabaseObject(DatabaseObjectType.VARIABLE)
{
Name = tokens[fileIndex].Text,
Database = InternalConstants.UNRELATED_DATABASE_NAME,
Schema = InternalConstants.UNRELATED_SCHEMA_NAME,
Server = InternalConstants.UNRELATED_SERVER_NAME
};
fileIndex++;
}
else if (tokens[fileIndex].Type.Equals(TSQLTokenType.StringLiteral) || tokens[fileIndex].Type.Equals(TSQLTokenType.NumericLiteral) || tokens[fileIndex].Type.Equals(TSQLTokenType.BinaryLiteral))
{
//The dbo is a set of constants e.g. ('Design Engineer', 'Tool Designer', 'Marketing Assistant')
var dataset = ResolvesDataSet(tokens, ref fileIndex, context);
dbo = new DatabaseObject(DatabaseObjectType.SET);
dbo.Expressions.Add(dataset);
}
else if (tokens[fileIndex].Text.Equals("openquery", StringComparison.InvariantCultureIgnoreCase))
{
dbo = new OpenQueryStatementResolver().Resolve(tokens, ref fileIndex, context);
}
else
{
throw new InvalidSqlException("Invalid database object");
}
SkipTableHints(tokens, ref fileIndex);
string alias = ResolveAlias(tokens, ref fileIndex, context);
if (!string.IsNullOrEmpty(alias))
{
dbo.Alias = alias;
}
SkipTableHints(tokens, ref fileIndex); //Table hints can appear before OR after an alias
return(dbo);
}
