Make interleave view work even with ridiculous column names

Author: mikebeaton

src/core/SqlDataComparison.sql

@@ -474,8 +474,8 @@ BEGIN
 	IF @interleave = 1
 	BEGIN
 		SELECT @sql = @sql +
-			@TAB + '   [ours].' + uc.quoted_name + ' AS [<<< ' + uc.quoted_name + '],' + @CRLF +
-			@TAB + '   [theirs].' + m.quoted_name + ' AS [>>> ' + m.quoted_name + '],' + @CRLF
+			@TAB + '   [ours].' + uc.quoted_name + ' AS ' + QUOTENAME('<<< ' + internals.MidAbbrev(PARSENAME(uc.quoted_name,1), 128 - 4)) + ',' + @CRLF +
+			@TAB + '   [theirs].' + m.quoted_name + ' AS ' + QUOTENAME('>>> ' + internals.MidAbbrev(PARSENAME(m.quoted_name,1), 128 - 4)) + ',' + @CRLF
 		FROM @use_columns uc
 		INNER JOIN @mapped_columns m
 		ON uc.column_id = m.column_id

src/preInternals/MidAbbrev.sql

@@ -0,0 +1,20 @@
+SET ANSI_NULLS ON
+GO
+SET QUOTED_IDENTIFIER ON
+GO
+/*[[LICENSE]]*/
+CREATE FUNCTION [internals].[MidAbbrev](
+	@string NVARCHAR(MAX),
+	@max_length INT
+)
+RETURNS sysname
+AS
+BEGIN
+	DECLARE @over INT = LEN(@string) - @max_length
+	IF @over > 0
+	BEGIN
+		SET @string = SUBSTRING(@string, 1, ((LEN(@string) - @over) / 2) - 1) + '...' + SUBSTRING(@string, ((LEN(@string) + @over)/2) + 3, LEN(@string))
+	END
+	RETURN @string
+END
+GO

tests/test-dbs/CreateCrazyTables.sql

@@ -61,7 +61,7 @@ EXEC(@SQL)
 
 SET @SQL = 
 	'CREATE TABLE ' + QUOTENAME(@longestname) + '.' + QUOTENAME(@longestname) + ' (' + @CRLF +
-	'	' + QUOTENAME(@longestname) + ' INT,' + @CRLF +
+	'	' + QUOTENAME(@longname) + ' INT,' + @CRLF +
 	'	' + QUOTENAME(@daftname1) + ' INT,' + @CRLF +
 	'	' + QUOTENAME(@daftname2) + ' NVARCHAR(50)' + @CRLF +
 	')' + @CRLF

tests/testCrazyTableNames.sql renamed to tests/testCrazyTables.sql

@@ -1,10 +1,10 @@
 USE SqlUtils
 GO
 
-EXEC tSQLt.NewTestClass 'testCrazyTableNames';
+EXEC tSQLt.NewTestClass 'testCrazyTables';
 GO
 
-CREATE PROCEDURE testCrazyTableNames.[test crazy table and column names]
+CREATE PROCEDURE testCrazyTables.[test crazy table and column names]
 AS
 BEGIN
 	SET NOCOUNT ON;
@@ -29,10 +29,10 @@ BEGIN
 	SET @SQL =
 		'EXEC ImportAll ''[SqlUtilsTests_A].' + QUOTENAME(@longestname) + '.' + QUOTENAME(@longestname) + ''', ''[SqlUtilsTests_C]..' + REPLACE(QUOTENAME(@longname), '''', '''''') + '''' + @CRLF +
 		', @join = ''' +
-		QUOTENAME(@longestname) + ', ' + REPLACE(QUOTENAME(@daftname1), '''', '''''') +
+		REPLACE(QUOTENAME(@longname), '''', '''''') + ', ' + REPLACE(QUOTENAME(@daftname1), '''', '''''') +
 		'''' + @CRLF +
 		', @map = ''' +
-		QUOTENAME(@longestname) + ', ' + REPLACE(QUOTENAME(@daftname2), '''', '''''') +
+		REPLACE(QUOTENAME(@longname), '''', '''''') + ', ' + REPLACE(QUOTENAME(@daftname2), '''', '''''') +
 		'; ' +
 		REPLACE(QUOTENAME(@daftname1), '''', '''''') + ', ' + QUOTENAME(@longestname) +
 		'; ' +

tests/testMidAbbrev.sql

@@ -0,0 +1,32 @@
+EXEC tSQLt.NewTestClass 'testMidAbbrev';
+GO
+
+CREATE PROCEDURE testMidAbbrev.internalTestMidAbbrev
+	@toAbbreviate NVARCHAR(MAX),
+	@length INT,
+	@expectedResult NVARCHAR(MAX)
+AS
+BEGIN
+	SET NOCOUNT ON;
+
+	DECLARE @len INT = LEN(@expectedResult)
+	EXEC tSQLt.AssertEquals @length, @len
+
+	DECLARE @abbreviated NVARCHAR(MAX) = internals.MidAbbrev(@toAbbreviate, @length)
+	EXEC tSQLt.AssertEqualsString @expectedResult, @abbreviated
+END
+GO
+
+CREATE PROCEDURE testMidAbbrev.[test MidAbbrev works]
+AS
+BEGIN
+	SET NOCOUNT ON;
+
+	EXEC testMidAbbrev.internalTestMidAbbrev '12345678', 3, '...'
+	EXEC testMidAbbrev.internalTestMidAbbrev '12345678', 4, '1...'
+	EXEC testMidAbbrev.internalTestMidAbbrev '12345678', 5, '1...8'
+	EXEC testMidAbbrev.internalTestMidAbbrev '12345678', 6, '12...8'
+	EXEC testMidAbbrev.internalTestMidAbbrev '12345678', 7, '12...78'
+	EXEC testMidAbbrev.internalTestMidAbbrev '12345678', 8, '12345678'
+END
+GO