Fixes #1365

HicServices · Aug 15, 2022 · baa124e · baa124e
1 parent f98845d
commit baa124e
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Showing 2 changed files with 38 additions and 3 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 - Removed restriction preventing [Lookup] requiring all foreign key columns being from the same table [#1331](https://github.com/HicServices/RDMP/issues/1307)
+- If there are multiple IsPrimaryExtractionTable involved in a query then the one with the IsExtractionIdentifier column (if any) will be picked (previously QueryBuildingException was thrown) [#1365](https://github.com/HicServices/RDMP/issues/1365)
 
 ### Added
 - Added 'Set Description' command to [AggregateConfiguration] context menu

diff --git a/Rdmp.Core/QueryBuilding/SqlQueryBuilderHelper.cs b/Rdmp.Core/QueryBuilding/SqlQueryBuilderHelper.cs
@@ -237,9 +237,7 @@ public static List<ITableInfo> GetTablesUsedInQuery(ISqlQueryBuilder qb, out ITa
                         if (primaryExtractionTable == null)
                             primaryExtractionTable = table;
                         else
-                            throw new QueryBuildingException("There are multiple tables marked as IsPrimaryExtractionTable:" +
-                                                primaryExtractionTable.Name + "(ID=" + primaryExtractionTable.ID +
-                                                ") and " + table.Name + "(ID=" + table.ID + ")");
+                            primaryExtractionTable = PickBestPrimaryExtractionTable(qb,primaryExtractionTable, table);
                 }
             }
 
@@ -268,6 +266,42 @@ public static List<ITableInfo> GetTablesUsedInQuery(ISqlQueryBuilder qb, out ITa
             return toReturn;
         }
 
+        /// <summary>
+        /// Picks between two <see cref="ITableInfo"/> both of which are <see cref="TableInfo.IsPrimaryExtractionTable"/> and returns
+        /// the 'winner' (best to start joining from).  Throws <see cref="QueryBuildingException"/> if there is no clear better one
+        /// </summary>
+        /// <param name="qb"></param>
+        /// <param name="t1"></param>
+        /// <param name="t2"></param>
+        /// <returns></returns>
+        /// <exception cref="QueryBuildingException"></exception>
+        private static ITableInfo PickBestPrimaryExtractionTable(ISqlQueryBuilder qb, ITableInfo t1, TableInfo t2)
+        {
+            // what tables have IsExtractionIdentifier column(s)? 
+            var extractionIdentifierTables = qb.SelectColumns
+                .Where(c => c.IColumn?.IsExtractionIdentifier ?? false)
+                .Select(t => t.UnderlyingColumn?.TableInfo_ID)
+                .Where(id => id != null)
+                .ToArray();
+
+            if(extractionIdentifierTables.Length == 1)
+            {
+                var id = extractionIdentifierTables[0];
+
+                if (id == t1.ID)
+                    return t1;
+
+                if (id == t2.ID)
+                    return t2;
+
+                // IsExtractionIdentifier column is from neither of these tables, bad times
+            }
+
+            throw new QueryBuildingException("There are multiple tables marked as IsPrimaryExtractionTable:" +
+                                                t1.Name + "(ID=" + t1.ID +
+                                                ") and " + t2.Name + "(ID=" + t2.ID + ")");
+        }
+
         private static List<ITableInfo> AddOpportunisticJoins(List<ITableInfo> toReturn, List<IFilter> filters)
         {
             //there must be at least one TableInfo here to do this... but we are going to look up all available JoinInfos from these tables to identify opportunistic joins