C# StandardProviderParameters类代码示例

        protected static string ApplyWhereSubOperations(StandardProviderParameters std, tgDynamicQuerySerializable query, tgComparison.tgComparisonData comparisonData)
        {
            string sql = string.Empty;

            if (comparisonData.HasExpression)
            {
                sql += GetMathmaticalExpressionColumn(std, query, comparisonData.Expression);

                if (comparisonData.SubOperators != null && comparisonData.SubOperators.Count > 0)
                {
                    sql = BuildSubOperationsSql(std, sql, comparisonData.SubOperators);
                }

                return sql;
            }

            string delimitedColumnName = GetColumnName(comparisonData.Column);

            if (comparisonData.SubOperators != null)
            {
                sql = BuildSubOperationsSql(std, delimitedColumnName, comparisonData.SubOperators);
            }
            else
            {
                sql = delimitedColumnName;
            }

            return sql;
        }

        public static VistaDBCommand PrepareCommand(tgDataRequest request)
        {
            StandardProviderParameters std = new StandardProviderParameters();
            std.cmd = new VistaDBCommand();
            std.pindex = NextParamIndex(std.cmd);
            std.request = request;

            string sql = BuildQuery(std, request.DynamicQuery);

            std.cmd.CommandText = sql;
            return (VistaDBCommand)std.cmd;
        }

        protected static string BuildQuery(StandardProviderParameters std, tgDynamicQuerySerializable query)
        {
            IDynamicQuerySerializableInternal iQuery = query as IDynamicQuerySerializableInternal;

            string select = GetSelectStatement(std, query);
            string from = GetFromStatement(std, query);
            string join = GetJoinStatement(std, query);
            string where = GetComparisonStatement(std, query, iQuery.InternalWhereItems, " WHERE ");
            string groupBy = GetGroupByStatement(std, query);
            string having = GetComparisonStatement(std, query, iQuery.InternalHavingItems, " HAVING ");
            string orderBy = GetOrderByStatement(std, query);
            string setOperation = GetSetOperationStatement(std, query);

            string sql = "SELECT " + select + " FROM " + from + join + where + setOperation + groupBy + having + orderBy;

            return sql;
        }

        protected static string GetComparisonStatement(StandardProviderParameters std, tgDynamicQuerySerializable query, List<tgComparison> items, string prefix)
        {
            string sql = String.Empty;
            string comma = String.Empty;

            IDynamicQuerySerializableInternal iQuery = query as IDynamicQuerySerializableInternal;

            //=======================================
            // WHERE
            //=======================================
            if (items != null)
            {
                sql += prefix;

                string compareTo = String.Empty;
                foreach (tgComparison comparisonItem in items)
                {
                    tgComparison.tgComparisonData comparisonData = (tgComparison.tgComparisonData)comparisonItem;
                    tgDynamicQuerySerializable subQuery = null;

                    bool requiresParam = true;
                    bool needsStringParameter = false;

                    if (comparisonData.IsParenthesis)
                    {
                        if (comparisonData.Parenthesis == tgParenthesis.Open)
                            sql += "(";
                        else
                            sql += ")";

                        continue;
                    }

                    if (comparisonData.IsConjunction)
                    {
                        switch (comparisonData.Conjunction)
                        {
                            case tgConjunction.And: sql += " AND "; break;
                            case tgConjunction.Or: sql += " OR "; break;
                            case tgConjunction.AndNot: sql += " AND NOT "; break;
                            case tgConjunction.OrNot: sql += " OR NOT "; break;
                        }
                        continue;
                    }

                    Dictionary<string, VistaDBParameter> types = null;
                    if (comparisonData.Column.Query != null)
                    {
                        IDynamicQuerySerializableInternal iLocalQuery = comparisonData.Column.Query as IDynamicQuerySerializableInternal;
                        types = Cache.GetParameters(iLocalQuery.DataID, (tgProviderSpecificMetadata)iLocalQuery.ProviderMetadata, (tgColumnMetadataCollection)iLocalQuery.Columns);
                    }

                    if (comparisonData.IsLiteral)
                    {
                        sql += comparisonData.Column.Name.Substring(1, comparisonData.Column.Name.Length - 2);
                        continue;
                    }

                    if (comparisonData.ComparisonColumn.Name == null)
                    {
                        subQuery = comparisonData.Value as tgDynamicQuerySerializable;

                        if (subQuery == null)
                        {
                            if (comparisonData.Column.Name != null)
                            {
                                IDynamicQuerySerializableInternal iColQuery = comparisonData.Column.Query as IDynamicQuerySerializableInternal;
                                tgColumnMetadataCollection columns = (tgColumnMetadataCollection)iColQuery.Columns;
                                compareTo = Delimiters.Param + columns[comparisonData.Column.Name].PropertyName + (++std.pindex).ToString();
                            }
                            else
                            {
                                compareTo = Delimiters.Param + "Expr" + (++std.pindex).ToString();
                            }
                        }
                        else
                        {
                            // It's a sub query
                            compareTo = GetSubquerySearchCondition(subQuery) + " (" + BuildQuery(std, subQuery) + ") ";
                            requiresParam = false;
                        }
                    }
                    else
                    {
                        compareTo = GetColumnName(comparisonData.ComparisonColumn);
                        requiresParam = false;
                    }

                    switch (comparisonData.Operand)
                    {
                        case tgComparisonOperand.Exists:
                            sql += " EXISTS" + compareTo;
                            break;
                        case tgComparisonOperand.NotExists:
                            sql += " NOT EXISTS" + compareTo;
                            break;

                        //-----------------------------------------------------------
                        // Comparison operators, left side vs right side
                        //-----------------------------------------------------------
//.........这里部分代码省略.........

        protected static string GetMathmaticalExpressionColumn(StandardProviderParameters std, tgDynamicQuerySerializable query, tgMathmaticalExpression mathmaticalExpression)
        {
            bool isMod = false;
            bool needsRounding = false;

            string sql = "(";

            if (mathmaticalExpression.ItemFirst)
            {
                sql += GetExpressionColumn(std, query, mathmaticalExpression.SelectItem1, true, false);
                sql += esArithmeticOperatorToString(mathmaticalExpression, out isMod, out needsRounding);

                if (mathmaticalExpression.SelectItem2 != null)
                {
                    sql += GetExpressionColumn(std, query, mathmaticalExpression.SelectItem2, true, false);
                }
                else
                {
                    sql += GetMathmaticalExpressionLiteralType(std, mathmaticalExpression);
                }
            }
            else
            {
                if (mathmaticalExpression.SelectItem2 != null)
                {
                    sql += GetExpressionColumn(std, query, mathmaticalExpression.SelectItem2, true, true);
                }
                else
                {
                    sql += GetMathmaticalExpressionLiteralType(std, mathmaticalExpression);
                }

                sql += esArithmeticOperatorToString(mathmaticalExpression, out isMod, out needsRounding);
                sql += GetExpressionColumn(std, query, mathmaticalExpression.SelectItem1, true, false);
            }

            sql += ")";

            if (isMod)
            {
                sql = "MOD(" + sql.Replace("(", String.Empty).Replace(")", String.Empty) + ")";
            }
            if (needsRounding)
            {
                sql = "ROUND(" + sql + ", 10)";
            }

            return sql;
        }

        protected static string GetOrderByStatement(StandardProviderParameters std, tgDynamicQuerySerializable query)
        {
            string sql = String.Empty;
            string comma = String.Empty;

            IDynamicQuerySerializableInternal iQuery = query as IDynamicQuerySerializableInternal;

            if (iQuery.InternalOrderByItems != null)
            {
                sql += " ORDER BY ";

                foreach (tgOrderByItem orderByItem in iQuery.InternalOrderByItems)
                {
                    bool literal = false;

                    sql += comma;

                    string columnName = orderByItem.Expression.Column.Name;

                    if (columnName != null && columnName[0] == '<')
                    {
                        sql += columnName.Substring(1, columnName.Length - 2);

                        if (orderByItem.Direction == tgOrderByDirection.Unassigned)
                        {
                            literal = true; // They must provide the DESC/ASC in the literal string
                        }
                    }
                    else
                    {
                        sql += GetExpressionColumn(std, query, orderByItem.Expression, false, false);
                    }

                    if (!literal)
                    {
                        if (orderByItem.Direction == tgOrderByDirection.Ascending)
                            sql += " ASC";
                        else
                            sql += " DESC";
                    }

                    comma = ",";
                }
            }

            return sql;
        }

        protected static string GetGroupByStatement(StandardProviderParameters std, tgDynamicQuerySerializable query)
        {
            string sql = String.Empty;
            string comma = String.Empty;

            IDynamicQuerySerializableInternal iQuery = query as IDynamicQuerySerializableInternal;

            if (iQuery.InternalGroupByItems != null)
            {
                sql += " GROUP BY ";

                foreach (tgGroupByItem groupBy in iQuery.InternalGroupByItems)
                {
                    sql += comma;

                    string columnName = groupBy.Expression.Column.Name;

                    if (columnName != null && columnName[0] == '<')
                        sql += columnName.Substring(1, columnName.Length - 2);
                    else
                        sql += GetExpressionColumn(std, query, groupBy.Expression, false, false);

                    comma = ",";
                }

                if (query.tg.WithRollup)
                {
                    sql += " WITH ROLLUP";
                }
            }

            return sql;
        }

        protected static string BuildQuery(StandardProviderParameters std, tgDynamicQuerySerializable query)
        {
            bool paging = false;

            if (query.tg.PageNumber.HasValue && query.tg.PageSize.HasValue)
                paging = true;

            IDynamicQuerySerializableInternal iQuery = query as IDynamicQuerySerializableInternal;

            string select = GetSelectStatement(std, query);
            string from = GetFromStatement(std, query);
            string join = GetJoinStatement(std, query);
            string where = GetComparisonStatement(std, query, iQuery.InternalWhereItems, " WHERE ");
            string groupBy = GetGroupByStatement(std, query);
            string having = GetComparisonStatement(std, query, iQuery.InternalHavingItems, " HAVING ");
            string orderBy = GetOrderByStatement(std, query);
            string setOperation = GetSetOperationStatement(std, query);

            string sql = String.Empty;

            sql += "SELECT " + select + " FROM " + from + join + where + setOperation + groupBy + having + orderBy;

            if (paging)
            {
                int begRow = ((query.tg.PageNumber.Value - 1) * query.tg.PageSize.Value);

                sql += " LIMIT " + query.tg.PageSize.ToString();
                sql += " OFFSET " + begRow.ToString() + " ";
            }
            else if (query.tg.Top >= 0)
            {
                sql += " LIMIT " + query.tg.Top.ToString() + " ";
            }
            else if (iQuery.Skip.HasValue || iQuery.Take.HasValue)
            {
                if (iQuery.Take.HasValue)
                {
                    sql += " LIMIT " + iQuery.Take.ToString() + " ";
                }

                if (iQuery.Skip.HasValue)
                {
                    sql += " OFFSET " + iQuery.Skip.ToString() + " ";
                }
            }

            return sql;
        }

        protected static string BuildSubOperationsSql(StandardProviderParameters std, string columnName, List<tgQuerySubOperator> subOperators)
        {
            string sql = string.Empty;

            subOperators.Reverse();

            Stack<object> stack = new Stack<object>();

            if (subOperators != null)
            {
                foreach (tgQuerySubOperator op in subOperators)
                {
                    switch (op.SubOperator)
                    {
                        case tgQuerySubOperatorType.ToLower:
                            sql += "LCase(";
                            stack.Push(")");
                            break;

                        case tgQuerySubOperatorType.ToUpper:
                            sql += "UCase(";
                            stack.Push(")");
                            break;

                        case tgQuerySubOperatorType.LTrim:
                            sql += "LTrim(";
                            stack.Push(")");
                            break;

                        case tgQuerySubOperatorType.RTrim:
                            sql += "RTrim(";
                            stack.Push(")");
                            break;

                        case tgQuerySubOperatorType.Trim:
                            sql += "Trim(";
                            stack.Push(")");
                            break;

                        case tgQuerySubOperatorType.SubString:

                            sql += "Mid(";

                            stack.Push(")");
                            stack.Push(op.Parameters["length"]);
                            stack.Push(",");

                            if (op.Parameters.ContainsKey("start"))
                            {
                                stack.Push(op.Parameters["start"]);
                                stack.Push(",");
                            }
                            else
                            {
                                // They didn't pass in start so we start
                                // at the beginning
                                stack.Push(1);
                                stack.Push(",");
                            }
                            break;

                        case tgQuerySubOperatorType.Coalesce:
                            sql += "Coalesce(";

                            stack.Push(")");
                            stack.Push(op.Parameters["expressions"]);
                            stack.Push(",");
                            break;

                        case tgQuerySubOperatorType.Date:
                            sql += "DATEADD(\"d\", 0, DATEDIFF(\"d\", 0,";

                            stack.Push("))");
                            break;
                        case tgQuerySubOperatorType.Length:
                            sql += "Len(";
                            stack.Push(")");
                            break;

                        case tgQuerySubOperatorType.Round:
                            sql += "Round(";

                            stack.Push(")");
                            stack.Push(op.Parameters["SignificantDigits"]);
                            stack.Push(",");
                            break;

                        case tgQuerySubOperatorType.DatePart:
                            sql += "DatePart(\"";
                            sql += op.Parameters["DatePart"];
                            sql += "\",";

                            stack.Push(")");
                            break;

                        case tgQuerySubOperatorType.Avg:
                            sql += "Round(Avg(";

                            stack.Push("), 10)");
                            break;
//.........这里部分代码省略.........

        protected static string GetJoinStatement(StandardProviderParameters std, tgDynamicQuerySerializable query)
        {
            string sql = String.Empty;

            IDynamicQuerySerializableInternal iQuery = query as IDynamicQuerySerializableInternal;

            if (iQuery.InternalJoinItems != null)
            {
                foreach (tgJoinItem joinItem in iQuery.InternalJoinItems)
                {
                    tgJoinItem.tgJoinItemData joinData = (tgJoinItem.tgJoinItemData)joinItem;

                    switch (joinData.JoinType)
                    {
                        case tgJoinType.InnerJoin:
                            sql += " INNER JOIN ";
                            break;
                        case tgJoinType.LeftJoin:
                            sql += " LEFT JOIN ";
                            break;
                        case tgJoinType.RightJoin:
                            sql += " RIGHT JOIN ";
                            break;
                        case tgJoinType.FullJoin:
                            sql += " FULL JOIN ";
                            break;
                    }

                    IDynamicQuerySerializableInternal iSubQuery = joinData.Query as IDynamicQuerySerializableInternal;

                    sql += Shared.CreateFullName((tgProviderSpecificMetadata)iSubQuery.ProviderMetadata);
                    sql += " " + iSubQuery.JoinAlias + " ON ";

                    foreach (tgComparison comparisonItem in joinData.WhereItems)
                    {
                        tgComparison.tgComparisonData comparisonData = (tgComparison.tgComparisonData)comparisonItem;

                        if (comparisonData.IsParenthesis)
                        {
                            if (comparisonData.Parenthesis == tgParenthesis.Open)
                                sql += "(";
                            else
                                sql += ")";

                            continue;
                        }

                        if (comparisonData.IsConjunction)
                        {
                            if (comparisonData.Conjunction == tgConjunction.And)
                                sql += " AND ";
                            else
                                sql += " OR ";

                            continue;
                        }

                        sql += GetColumnName(comparisonData.Column);

                        switch (comparisonData.Operand)
                        {
                            case tgComparisonOperand.Equal:
                                sql += " = ";
                                break;
                            case tgComparisonOperand.NotEqual:
                                sql += " <> ";
                                break;
                            case tgComparisonOperand.GreaterThan:
                                sql += " > ";
                                break;
                            case tgComparisonOperand.LessThan:
                                sql += " < ";
                                break;
                            case tgComparisonOperand.LessThanOrEqual:
                                sql += " <= ";
                                break;
                            case tgComparisonOperand.GreaterThanOrEqual:
                                sql += " >= ";
                                break;
                            case tgComparisonOperand.IsNull:
                                sql += " IS NULL ";
                                break;
                            case tgComparisonOperand.IsNotNull:
                                sql += " IS NOT NULL ";
                                break;
                            case tgComparisonOperand.In:
                                sql += " IN ";
                                break;
                            case tgComparisonOperand.NotIn:
                                sql += " NOT IN ";
                                break;
                        }

                        if (comparisonData.ComparisonColumn.Name != null)
                        {
                            sql += GetColumnName(comparisonData.ComparisonColumn);
                        }
                        else
                        {
                            tgDynamicQuerySerializable subQuery = comparisonData.Value as tgDynamicQuerySerializable;
//.........这里部分代码省略.........

        protected static string GetExpressionColumn(StandardProviderParameters std, tgDynamicQuerySerializable query, tgExpression expression, bool inExpression, bool useAlias)
        {
            string sql = String.Empty;

            if (expression.CaseWhen != null)
            {
                return GetCaseWhenThenEnd(std, query, expression.CaseWhen);
            }

            if (expression.HasMathmaticalExpression)
            {
                sql += GetMathmaticalExpressionColumn(std, query, expression.MathmaticalExpression);
            }
            else
            {
                sql += GetColumnName(expression.Column);
            }

            if (expression.SubOperators != null)
            {
                if (expression.Column.Distinct)
                {
                    sql = BuildSubOperationsSql(std, "DISTINCT " + sql, expression.SubOperators);
                }
                else
                {
                    sql = BuildSubOperationsSql(std, sql, expression.SubOperators);
                }
            }

            if (!inExpression && useAlias)
            {
                if (expression.SubOperators != null || expression.Column.HasAlias)
                {
                    sql += " AS " + Delimiters.StringOpen + expression.Column.Alias + Delimiters.StringClose;
                }
            }

            return sql;
        }

        protected static string GetFromStatement(StandardProviderParameters std, tgDynamicQuerySerializable query)
        {
            IDynamicQuerySerializableInternal iQuery = query as IDynamicQuerySerializableInternal;

            string sql = String.Empty;

            if (iQuery.InternalFromQuery == null)
            {
                sql = Shared.CreateFullName(query);

                if (iQuery.JoinAlias != " ")
                {
                    sql += " " + iQuery.JoinAlias;
                }
            }
            else
            {
                IDynamicQuerySerializableInternal iSubQuery = iQuery.InternalFromQuery as IDynamicQuerySerializableInternal;

                iSubQuery.IsInSubQuery = true;

                sql += "(";
                sql += BuildQuery(std, iQuery.InternalFromQuery);
                sql += ")";

                if (iSubQuery.SubQueryAlias != " ")
                {
                    sql += " AS " + iSubQuery.SubQueryAlias;
                }

                iSubQuery.IsInSubQuery = false;
            }

            return sql;
        }

        protected static string GetSetOperationStatement(StandardProviderParameters std, tgDynamicQuerySerializable query)
        {
            string sql = String.Empty;

            IDynamicQuerySerializableInternal iQuery = query as IDynamicQuerySerializableInternal;

            if (iQuery.InternalSetOperations != null)
            {
                foreach (tgSetOperation setOperation in iQuery.InternalSetOperations)
                {
                    switch (setOperation.SetOperationType)
                    {
                        case tgSetOperationType.Union: sql += " UNION "; break;
                        case tgSetOperationType.UnionAll: sql += " UNION ALL "; break;
                        case tgSetOperationType.Intersect: sql += " INTERSECT "; break;
                        case tgSetOperationType.Except: sql += " EXCEPT "; break;
                    }

                    sql += BuildQuery(std, setOperation.Query);
                }
            }

            return sql;
        }

        protected static string GetMathmaticalExpressionLiteralType(StandardProviderParameters std, tgMathmaticalExpression mathmaticalExpression)
        {
            switch (mathmaticalExpression.LiteralType)
            {
                case tgSystemType.String:
                    return Delimiters.StringOpen + (string)mathmaticalExpression.Literal + Delimiters.StringClose;

                case tgSystemType.DateTime:
                    return Delimiters.StringOpen + ((DateTime)(mathmaticalExpression.Literal)).ToShortDateString() + Delimiters.StringClose;

                default:
                    return Convert.ToString(mathmaticalExpression.Literal);
            }
        }

        protected static string GetCaseWhenThenEnd(StandardProviderParameters std, tgDynamicQuerySerializable query, tgCase caseWhenThen)
        {
            string sql = string.Empty;

            Tiraggo.DynamicQuery.tgCase.tgSimpleCaseData caseStatement = caseWhenThen;

            tgColumnItem column = caseStatement.QueryItem;

            sql += "CASE ";

            List<tgComparison> list = new List<tgComparison>();

            foreach (Tiraggo.DynamicQuery.tgCase.tgSimpleCaseData.tgCaseClause caseClause in caseStatement.Cases)
            {
                sql += " WHEN ";
                if (!caseClause.When.IsExpression)
                {
                    sql += GetComparisonStatement(std, query, caseClause.When.Comparisons, string.Empty);
                }
                else
                {
                    if (!caseClause.When.Expression.IsLiteralValue)
                    {
                        sql += GetExpressionColumn(std, query, caseClause.When.Expression, false, true);
                    }
                    else
                    {
                        if (caseClause.When.Expression.LiteralValue is string)
                        {
                            sql += Delimiters.StringOpen + caseClause.When.Expression.LiteralValue + Delimiters.StringClose;
                        }
                        else
                        {
                            sql += Convert.ToString(caseClause.When.Expression.LiteralValue);
                        }
                    }
                }

                sql += " THEN ";

                if (!caseClause.Then.IsLiteralValue)
                {
                    sql += GetExpressionColumn(std, query, caseClause.Then, false, true);
                }
                else
                {
                    if (caseClause.Then.LiteralValue is string)
                    {
                        sql += Delimiters.StringOpen + caseClause.Then.LiteralValue + Delimiters.StringClose;
                    }
                    else
                    {
                        sql += Convert.ToString(caseClause.Then.LiteralValue);
                    }
                }
            }

            if (caseStatement.Else != null)
            {
                sql += " ELSE ";

                if (!caseStatement.Else.IsLiteralValue)
                {
                    sql += GetExpressionColumn(std, query, caseStatement.Else, false, true);
                }
                else
                {
                    if (caseStatement.Else.LiteralValue is string)
                    {
                        sql += Delimiters.StringOpen + caseStatement.Else.LiteralValue + Delimiters.StringClose;
                    }
                    else
                    {
                        sql += Convert.ToString(caseStatement.Else.LiteralValue);
                    }
                }
            }

            sql += " END ";
            sql += " AS " + Delimiters.ColumnOpen + column.Alias + Delimiters.ColumnClose;

            return sql;
        }