chore: initial git load of code space

2026-05-12 08:52:33 -05:00
parent 9abada692f
commit 5e467bcc9c
384 changed files with 65960 additions and 2 deletions
@@ -0,0 +1,146 @@
+using System.Text;
+using Strata.SqlTools.Breakdowns.SqlServer;
+using Strata.SqlTools.SqlBreakdown.Interfaces.QueryEngine;
+
+namespace Strata.SqlTools.SqlServer.Utilities;
+
+/// <summary>
+/// SQL Server-specific paging helper methods for generating paged query results.
+/// </summary>
+public static class SqlServerPagingUtils
+{
+    /// <summary>
+    /// Generates SQL for paged result sets.
+    /// </summary>
+    /// <param name="queryBreakdown">The query breakdown defining the SQL query.</param>
+    /// <param name="pageIndex">The zero-based page index.</param>
+    /// <param name="pageSize">The number of rows per page.</param>
+    /// <param name="rowNumOrderBy">The ORDER BY clause for row numbering.</param>
+    /// <returns>A SQL string that implements paging.</returns>
+    public static string GetPagingSql(IQueryBreakdown queryBreakdown, int pageIndex, int pageSize, string rowNumOrderBy)
+    {
+        bool isPaged = pageIndex != -1;
+        var sb = new StringBuilder();
+        string finalTable = "#FINALTABLE" + Guid.NewGuid().ToString().Replace("-", string.Empty);
+
+        // Write out any setup clauses
+        sb.AppendLine("--create setup clauses");
+        foreach (string setup in queryBreakdown.SetupClauses)
+        {
+            sb.AppendLine(setup);
+        }
+
+        // Get the data
+        sb.AppendLine("--get the data");
+        if (isPaged)
+        {
+            sb.Append($"SELECT Row_Number() Over (Order By {rowNumOrderBy}) as ROWNUM,");
+            sb.AppendLine();
+            sb.Append($"{queryBreakdown.SelectClause} INTO {finalTable} FROM {queryBreakdown.FromClause}");
+            sb.AppendLine();
+
+            if (queryBreakdown.IsUsingWhereClause)
+            {
+                sb.Append($"WHERE {queryBreakdown.WhereClause}");
+                sb.AppendLine();
+            }
+        }
+        else
+        {
+            sb.AppendLine("SELECT");
+            sb.Append($"{queryBreakdown.SelectClause} INTO {finalTable} FROM {queryBreakdown.FromClause}");
+            sb.AppendLine();
+
+            if (queryBreakdown.IsUsingWhereClause)
+            {
+                sb.Append($"WHERE {queryBreakdown.WhereClause}");
+                sb.AppendLine();
+            }
+        }
+
+        if (queryBreakdown.IsUsingGroupByClause)
+        {
+            sb.Append(" GROUP BY ");
+            sb.AppendLine();
+            sb.Append($"          {queryBreakdown.GroupByClause} ");
+            sb.AppendLine();
+        }
+
+        if (queryBreakdown.IsUsingOrderByClause)
+        {
+            sb.Append($"ORDER BY {queryBreakdown.OrderByClause}");
+            sb.AppendLine();
+        }
+
+        if (isPaged)
+        {
+            sb.Append($"SELECT * FROM {finalTable} WHERE ROWNUM BETWEEN ({pageIndex} * {pageSize} + 1) and ({pageSize} * ({pageIndex} + 1))");
+            sb.AppendLine();
+        }
+        else
+        {
+            sb.Append($"SELECT * FROM {finalTable}");
+            sb.AppendLine();
+        }
+
+        sb.Append($"SELECT COUNT(*) FROM {finalTable}");
+        sb.AppendLine();
+
+        // Drop temp tables
+        sb.AppendLine("--drop temp tables");
+        sb.Append($"drop table {finalTable}");
+        sb.AppendLine();
+
+        // Write out any finish clauses
+        sb.AppendLine("--create finish clauses");
+        foreach (string finish in queryBreakdown.FinishClauses)
+        {
+            sb.AppendLine(finish);
+        }
+
+        return sb.ToString();
+    }
+
+    /// <summary>
+    /// Generate SQL to do paging. TotalCount will be returned as first column in the result set.
+    /// Uses Common Table Expression (CTE) for efficient paging with ROW_NUMBER() and COUNT(*) OVER().
+    /// </summary>
+    /// <param name="queryBreakdown">The query breakdown defining the SQL query.</param>
+    /// <param name="start">The starting row number (1-based).</param>
+    /// <param name="limit">The maximum number of rows to return.</param>
+    /// <param name="sort">The ORDER BY expression for sorting.</param>
+    /// <returns>A SQL string that implements paging with total count.</returns>
+    public static string GetPagingSqlByStart(IQueryBreakdown queryBreakdown, int start, int limit, string sort)
+    {
+        const string rowNumAlias = "RowNum";
+        const string totalCountAlias = "TotalCount";
+
+        // Setup innerQuery
+        const string innerQueryAlias = "Query";
+        var innerQuery = (IQueryBreakdown)((ICloneable)queryBreakdown).Clone();
+
+        var innerSelectSb = new StringBuilder();
+        innerSelectSb.Append($"ROW_NUMBER() OVER(ORDER BY {sort}) AS {rowNumAlias}, ");
+        innerSelectSb.AppendLine();
+        innerSelectSb.Append($"COUNT(*) OVER () AS {totalCountAlias}, ");
+        innerSelectSb.AppendLine(((QueryBreakdown)queryBreakdown).SelectClause.Clause);
+        ((QueryBreakdown)innerQuery).SelectClause.Clause = innerSelectSb.ToString();
+
+        // Setup pagingQuery
+        var pagingQuery = new QueryBreakdown();
+        pagingQuery.SelectClause.Clause = "*";
+        pagingQuery.FromClause.Clause = innerQueryAlias;
+        pagingQuery.WhereClause.Clause = $"{rowNumAlias} BETWEEN {start} AND ({start} + {limit}) - 1";
+
+        // Setup finalQuery with CTE
+        var sb = new StringBuilder();
+        sb.Append($";WITH {innerQueryAlias} AS ");
+        sb.AppendLine();
+        sb.AppendLine("( ");
+        sb.AppendLine(innerQuery.GetSql());
+        sb.AppendLine(") ");
+        sb.AppendLine(pagingQuery.GetSql(false));
+
+        return sb.ToString();
+    }
+}