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added marr.datamapper source code for easy debugging.

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kay.one 2013-03-30 14:56:34 -07:00
parent 58a05fcef8
commit 3cdff3bb71
96 changed files with 9198 additions and 363 deletions
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239
Marr.Data/QGen/PagingQueryDecorator.cs Normal file
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Marr.Data.Mapping;
using Marr.Data.QGen.Dialects;
namespace Marr.Data.QGen
{
/// <summary>
/// Decorates the SelectQuery by wrapping it in a paging query.
/// </summary>
public class PagingQueryDecorator : IQuery
{
private SelectQuery _innerQuery;
private int _firstRow;
private int _lastRow;
public PagingQueryDecorator(SelectQuery innerQuery, int skip, int take)
{
if (string.IsNullOrEmpty(innerQuery.OrderBy.ToString()))
{
throw new DataMappingException("A paged query must specify an order by clause.");
}
_innerQuery = innerQuery;
_firstRow = skip + 1;
_lastRow = skip + take;
}
public string Generate()
{
// Decide which type of paging query to create
if (_innerQuery.IsView || _innerQuery.IsJoin)
{
return ComplexPaging();
}
else
{
return SimplePaging();
}
}
/// <summary>
/// Generates a query that pages a simple inner query.
/// </summary>
/// <returns></returns>
private string SimplePaging()
{
// Create paged query
StringBuilder sql = new StringBuilder();
sql.AppendLine("WITH RowNumCTE AS");
sql.AppendLine("(");
_innerQuery.BuildSelectClause(sql);
BuildRowNumberColumn(sql);
_innerQuery.BuildFromClause(sql);
_innerQuery.BuildJoinClauses(sql);
_innerQuery.BuildWhereClause(sql);
sql.AppendLine(")");
BuildSimpleOuterSelect(sql);
return sql.ToString();
}
/// <summary>
/// Generates a query that pages a view or joined inner query.
/// </summary>
/// <returns></returns>
private string ComplexPaging()
{
// Create paged query
StringBuilder sql = new StringBuilder();
sql.AppendLine("WITH GroupCTE AS (");
BuildSelectClause(sql);
BuildGroupColumn(sql);
_innerQuery.BuildFromClause(sql);
_innerQuery.BuildJoinClauses(sql);
_innerQuery.BuildWhereClause(sql);
sql.AppendLine("),");
sql.AppendLine("RowNumCTE AS (");
sql.AppendLine("SELECT *");
BuildRowNumberColumn(sql);
sql.AppendLine("FROM GroupCTE");
sql.AppendLine("WHERE GroupRow = 1");
sql.AppendLine(")");
_innerQuery.BuildSelectClause(sql);
_innerQuery.BuildFromClause(sql);
_innerQuery.BuildJoinClauses(sql);
BuildJoinBackToCTE(sql);
sql.AppendFormat("WHERE RowNumber BETWEEN {0} AND {1}", _firstRow, _lastRow);
return sql.ToString();
}
private void BuildJoinBackToCTE(StringBuilder sql)
{
Table baseTable = GetBaseTable();
sql.AppendLine("INNER JOIN RowNumCTE cte");
int pksAdded = 0;
foreach (var pk in baseTable.Columns.PrimaryKeys)
{
if (pksAdded > 0)
sql.Append(" AND ");
string cteQueryPkName = _innerQuery.NameOrAltName(pk.ColumnInfo);
string outerQueryPkName = _innerQuery.IsJoin ? pk.ColumnInfo.Name : _innerQuery.NameOrAltName(pk.ColumnInfo);
sql.AppendFormat("ON cte.{0} = {1} ", cteQueryPkName, _innerQuery.Dialect.CreateToken(string.Concat("t0", ".", outerQueryPkName)));
pksAdded++;
}
sql.AppendLine();
}
private void BuildSimpleOuterSelect(StringBuilder sql)
{
sql.Append("SELECT ");
int startIndex = sql.Length;
// COLUMNS
foreach (Table join in _innerQuery.Tables)
{
for (int i = 0; i < join.Columns.Count; i++)
{
var c = join.Columns[i];
if (sql.Length > startIndex)
sql.Append(",");
string token = _innerQuery.NameOrAltName(c.ColumnInfo);
sql.Append(_innerQuery.Dialect.CreateToken(token));
}
}
sql.AppendLine("FROM RowNumCTE");
sql.AppendFormat("WHERE RowNumber BETWEEN {0} AND {1}", _firstRow, _lastRow).AppendLine();
sql.AppendLine("ORDER BY RowNumber ASC;");
}
private void BuildGroupColumn(StringBuilder sql)
{
bool isView = _innerQuery.IsView;
sql.AppendFormat(", ROW_NUMBER() OVER (PARTITION BY {0} {1}) As GroupRow ", BuildBaseTablePKColumns(isView), _innerQuery.OrderBy.BuildQuery(isView));
}
private string BuildBaseTablePKColumns(bool useAltName = true)
{
Table baseTable = GetBaseTable();
StringBuilder sb = new StringBuilder();
foreach (var col in baseTable.Columns.PrimaryKeys)
{
if (sb.Length > 0)
sb.AppendLine(", ");
string columnName = useAltName ?
_innerQuery.NameOrAltName(col.ColumnInfo) :
col.ColumnInfo.Name;
sb.AppendFormat(_innerQuery.Dialect.CreateToken(string.Concat(baseTable.Alias, ".", columnName)));
}
return sb.ToString();
}
private void BuildRowNumberColumn(StringBuilder sql)
{
string orderBy = _innerQuery.OrderBy.ToString();
// Remove table prefixes from order columns
foreach (Table t in _innerQuery.Tables)
{
orderBy = orderBy.Replace(string.Format("[{0}].", t.Alias), "");
}
sql.AppendFormat(", ROW_NUMBER() OVER ({0}) As RowNumber ", orderBy);
}
private Table GetBaseTable()
{
Table baseTable = null;
if (_innerQuery.Tables[0] is View)
{
baseTable = (_innerQuery.Tables[0] as View).Tables[0];
}
else
{
baseTable = _innerQuery.Tables[0];
}
return baseTable;
}
public void BuildSelectClause(StringBuilder sql)
{
List<string> appended = new List<string>();
sql.Append("SELECT ");
int startIndex = sql.Length;
// COLUMNS
foreach (Table join in _innerQuery.Tables)
{
for (int i = 0; i < join.Columns.Count; i++)
{
var c = join.Columns[i];
if (sql.Length > startIndex && sql[sql.Length - 1] != ',')
sql.Append(",");
if (join is View)
{
string token = _innerQuery.Dialect.CreateToken(string.Concat(join.Alias, ".", _innerQuery.NameOrAltName(c.ColumnInfo)));
if (appended.Contains(token))
continue;
sql.Append(token);
appended.Add(token);
}
else
{
string token = string.Concat(join.Alias, ".", c.ColumnInfo.Name);
if (appended.Contains(token))
continue;
sql.Append(_innerQuery.Dialect.CreateToken(token));
if (_innerQuery.UseAltName && c.ColumnInfo.AltName != null && c.ColumnInfo.AltName != c.ColumnInfo.Name)
{
string altName = c.ColumnInfo.AltName;
sql.AppendFormat(" AS {0}", altName);
}
}
}
}
}
}
}