Fields from "main" table not in SELECT no longer returned by INNER JOINs that require them.

 * For example, `SELECT field1, field2, table2.field1 FROM table1 INNER JOIN table2 ON table1.t2Id = table2.id` will no longer return `table1.t2Id`.
 * It does, however, still return `table2.id`, which I'll take a look at next (and potentially not increment the version).
 * The method used here is particularly bullheaded, spaghetti-ish, and inane:
    Added section to `_parseSelectStatement` in CommandParts that for fields in JOIN that belong to the "main" table.
    `_getColumnsToReturn` sees which of those are already in the SELECT and removes them from the CommandParts' lstrMainTableJoinONLYFields
    It also adds any columns not in the SELECT, but ignores any fuzzy name ramifications throughout.

    SelectCommand's executeStatement then adds a step to its POST-PROCESS INNER JOINS section, where it removes any columns from the main table in the JOIN but not in the SELECT, from the DataTable before returning it. So it *is* pulling the join fields back before taking them out.

Not exceptionally well tested. Will try to set more up when I take out fields from joined tables as well.

Author: ruffin--

BinaryReaderPlay/Main.cs

@@ -20,8 +20,8 @@ public class MainClass
     // Right now, on Windows, that's "C:\\Users\\YourUserName\\Documents\\MooresDbPlay"
     //public static readonly string cstrDbDir = Utils.cstrHomeDir + Path.DirectorySeparatorChar + "MooresDbPlay";
     public static bool bDebug = false;
-    public static string buildData = "20150410";    // not always incremented with each build.
-    public static string version = "0.0.4.2";
+    public static string buildData = "20150513";    // not always incremented with each build.
+    public static string version = "0.0.4.3";
 
     public static void logIt(string strMsg)
     {

BinaryReaderPlay/org/rufwork/mooresDb/infrastructure/commands/Processors/CommandParts.cs

@@ -6,6 +6,7 @@
 using org.rufwork.mooresDb.infrastructure.contexts;
 using org.rufwork.mooresDb.infrastructure.tableParts;
 using org.rufwork.extensions;
+using org.rufwork.mooresDb.exceptions;
 
 namespace org.rufwork.mooresDb.infrastructure.commands.Processors
 {
@@ -27,6 +28,7 @@ public class CommandParts
 
         public Column[] acolInSelect;
         public Queue<string> qstrAllColumnNames = new Queue<string>();
+        public List<string> lstrMainTableJoinONLYFields = new List<string>();   // Sir Not Well Named in this Film.
         public Dictionary<string, string> dictUpdateColVals = new Dictionary<string, string>();
         public Dictionary<string, string> dictFuzzyToColNameMappings = new Dictionary<string, string>();
         public Dictionary<string, string> dictRawNamesToASNames = new Dictionary<string, string>();
@@ -133,7 +135,7 @@ private void _parseSelectStatement(string strSql)
                 this.strFrom = strSql.Substring(intIndexOf, intTail - intIndexOf);
 
                 // Look for inner join.
-                // TODO: Another reserved word that we don't really want a table to be named ("join").
+                // TODO: Another reserved word that we don't really want a table to be named: ("join").
                 this.strInnerJoinKludge = "";
                 if (this.strFrom.IndexOf(" join ", StringComparison.CurrentCultureIgnoreCase) > -1)
                 {
@@ -143,8 +145,22 @@ private void _parseSelectStatement(string strSql)
                         this.strInnerJoinKludge = this.strFrom.Substring(intInnerJoin);
                         this.strFrom = this.strFrom.Substring(0, intInnerJoin);
 
-                        // TODO: Check the WHERE clause to see if anything belongs to the JOIN.
-                        //do that ^^^
+                        // Keep track of the join fields so we can intelligently select but
+                        // not display them if they are/aren't in the SELECT.
+                        // Let's start with the bullheaded way.
+                        string strMainTableName = this.strFrom.Substring(4).Trim();
+                        string[] innerKludgeTokenized = this.strInnerJoinKludge.Split();
+                        foreach (string toke in innerKludgeTokenized)
+                        {
+                            if (toke.ToUpper().StartsWith(strMainTableName.ToUpper()))
+                            {
+                                this.lstrMainTableJoinONLYFields.Add(toke.ReplaceCaseInsensitiveFind(strMainTableName + ".", ""));
+                            }
+                        }
+                    }
+                    else
+                    {
+                        throw new SyntaxException("Statement includes `join` keyword. Currently, only inner joins are supported.");
                     }
                 }
 
@@ -163,7 +179,38 @@ private void _parseSelectStatement(string strSql)
         private void _getColumnsToReturn()
         {
             Queue<Column> qCols = new Queue<Column>();
-            string[] astrCmdTokens = this.strSelect.StringToNonWhitespaceTokens2().Skip(1).ToArray();   // Skip 1 to ignore SELECT.
+            List<string> lstrCmdTokens = this.strSelect.StringToNonWhitespaceTokens2().Skip(1).ToList();   // Skip 1 to ignore SELECT.
+
+            if (!string.IsNullOrEmpty(this.strInnerJoinKludge))
+            {
+                // TODO: Clean this kludge to get in INNER JOIN fields into datatable
+                // while selecting, but to remove these once we're done before
+                // returning the DataTable.
+                // NOTE: I'm not taking into account fuzzily matching names, in part
+                // because I'm planning to remove that painful feature.
+                if (lstrCmdTokens.Contains("*"))
+                {
+                    // If we're selecting everything from the main table,
+                    // no additional columns are needed.
+                    this.lstrMainTableJoinONLYFields = new List<string>();
+                }
+                else
+                {
+                    foreach (string strMainTableCol in lstrCmdTokens.Where(s => !s.Contains(".") && !s.Contains("*")))
+                    {
+                        if (this.lstrMainTableJoinONLYFields.Contains(strMainTableCol))
+                        {
+                            this.lstrMainTableJoinONLYFields.Remove(strMainTableCol);
+                        }
+                    }
+                }
+
+                foreach (string strJoinColName in this.lstrMainTableJoinONLYFields)
+                {
+                    lstrCmdTokens.Add(strJoinColName);
+                }
+            }   // end kludge for grafting main table join fields not explicitly in SELECT list.
+            string[] astrCmdTokens = lstrCmdTokens.ToArray();
 
             for (int i = 0; i < astrCmdTokens.Length; i++)
             {

BinaryReaderPlay/org/rufwork/mooresDb/infrastructure/commands/SelectCommand.cs

@@ -65,11 +65,15 @@ public DataTable executeStatement(string strSql)
 
             WhereProcessor.ProcessRows(ref dtReturn, _table, selectParts);
 
+
+            //=====================================================================
+            // POST-PROCESS INNER JOINS
             // (Joins are only in selects, so this isn't part of WhereProcessing.)
             //
             // To take account of joins, we basically need to create a SelectParts
             // per inner join.  So we need to create a WHERE from the table we 
             // just selected and then send those values down to a new _selectRows.
+            //=====================================================================
             if (selectParts.strInnerJoinKludge.Length > 0)
             {
                 if (selectParts.qInnerJoinFields.Count < 1)
@@ -96,12 +100,27 @@ public DataTable executeStatement(string strSql)
                     {
                         dtReturn.Columns[astrFromSelect[i]].SetOrdinal(i);
                     }
+
+                    // TODO: There are better ways to do this.
+                    // TODO: Figure out if this handles all fuzzy name translations
+                    // earlier in the SELECT process.
+                    if (selectParts.lstrMainTableJoinONLYFields.Count() > 0)
+                    {
+                        foreach (string colName in selectParts.lstrMainTableJoinONLYFields)
+                        {
+                            dtReturn.Columns.Remove(colName);
+                        }
+                    }
                 }
                 catch (Exception e)
                 {
                     throw new SyntaxException("Problem reordering columns in inner join -- " + e.ToString());
                 }
             }
+            //=====================================================================
+            // EO POST-PROCESS INNER JOINS
+            //=====================================================================
+
 
             // strOrderBy has had all whitespace shortened to one space, so we can get away with the hardcoded 9.
             if (null != selectParts.strOrderBy && selectParts.strOrderBy.Length > 9)

ISQL/org/rufwork/mooresDb/clients/Isql.cs

@@ -198,7 +198,7 @@ INNER JOIN rest
 
                                     if (objResult is DataTable)
                                     {
-                                        Console.WriteLine(InfrastructureUtils.dataTableToString((DataTable)objResult, intWindowWidth));
+                                        Console.WriteLine(InfrastructureUtils.dataTableToString((DataTable)objResult, intWindowWidth-1));
                                     }
                                     else if (objResult is string)
                                     {

ReleaseNotes.md

@@ -1,6 +1,13 @@
 #Release notes:
 <br>
 
+##0.0.4.3 - 20150513
+
+* Fields from "main" table not explicitly mentioned in the SELECT are no longer returned by INNER JOINs that require them.
+	* For example, `SELECT field1, field2, table2.field1 FROM table1 INNER JOIN table2 ON table1.t2Id = table2.id` will no longer return `table1.t2Id`. 
+	* It does, however, still return `table2.id`, which I'll take a look at next (and potentially not increment the version).
+	* The method used here is particularly bullheaded, spaghetti-ish, and inane.
+
 ##0.0.4.2 - 20150410
 
 * `AS` support for *columns only* added.