Mis usuarios encuentran la solución "XML PATH" e intentan usarla, pero no son programadores y se confunden. En lugar de tratar de ayudarlos a aprender a usar la RUTA XML, creé un procedimiento que toma el nombre de una tabla y devuelve una cadena que contiene el marcado HTML para mostrar la tabla como una tabla HTML. Mi solución deriva dinámicamente los nombres de columna de la tabla HTML de la fuente de datos.
Ejemplo de uso del procedimiento HtmlTable
CREATE table ##foo (bar1 int, bar2 varchar(20), bar3 datetime)
INSERT into ##foo values (1, 'Abcdef', getdate())
INSERT into ##foo values (2, 'Ghijkl', '05/05/15')
DECLARE @tableHtml varchar(max)
EXEC dbo.HtmlTable
'##foo',
@tableHtml output
PRINT @tableHtml
La variable @tableHtml solo contiene marcas para una tabla HTML, lo cual es apropiado para incluir en un cuerpo de correo electrónico. Para ver solo, debe ajustar la salida con etiquetas html, head y body.
Salida del procedimiento HtmlTable
Código para el procedimiento HtmlTable
/*
Author: Leigh Haynes
Date: February 2015
Notes: Takes a table name as string parameter and returns a string that contains HTML markup to display the table contents as an HTML table.
The input table should be sorted before invoking HtmlTable.
*/
CREATE PROCEDURE [dbo].[HtmlTable]
@data_source varchar (100) = NULL,
@tableHTML varchar(max) OUTPUT
AS
BEGIN
SET NOCOUNT ON;
DECLARE
@db varchar(50),
@table varchar(100),
@cmd varchar(400),
@rcd_cnt int,
@sql nvarchar(1000);
--use procedure DataSourceCheck to see if @data_source is valid
EXEC dbo.DataSourceCheck @data_source, @db output, @table output;
IF @db is NULL --if the data source is not good, @db comes back NULL, and @table holds info as to the problem (either the table does not exist, or it is empty).
BEGIN
SET @tableHtml = @table;
RETURN;
END;
--We have a good table. Use information_schema metadata for table to get column names.
IF OBJECT_ID ('tempdb..##columnNames') IS not null DROP TABLE ##columnNames;
CREATE table ##columnNames (column_name varchar(50), position int identity);
SET @sql = 'USE ' + @db + '; INSERT into ##columnNames SELECT column_name from information_schema.columns where table_name = ''' + @table + ''' order by ordinal_position';
EXEC master.sys.sp_executesql @sql;
--use ##columnNames to create table ##columnPivot with the proper number of fields to hold data
IF OBJECT_ID ('tempdb..##columnPivot') IS not null DROP TABLE ##columnPivot;
CREATE table ##columnPivot (f1 varchar(200));
DECLARE
@i int = 2,
@fieldct int,
@column varchar(50),
@field varchar(200),
@value varchar(100),
@html varchar(max) = '';
SET @fieldct = (SELECT COUNT(*) from ##columnNames);
WHILE @i <= @fieldct --loop through adding a field to ##columnPivot for each column. Max field len is 200.
BEGIN
SET @sql = 'ALTER table ##columnPivot ADD f' + cast (@i as varchar(2)) + ' varchar(200)';
EXEC master.sys.sp_executesql @sql;
SET @i = @i + 1;
END
--##columnPivot is constructed but empty. Columns are named f1, f2, f3, etc
--construct dynamic SQL string that will be executed to populate ##columnPivot
SET @sql = 'INSERT into ##columnPivot SELECT ';
SET @i = 1;
SET @fieldct = (SELECT count(*) from ##columnNames);
WHILE @i <= @fieldct - 1
BEGIN
SET @column = (SELECT top 1 column_name from ##columnNames where position = cast (@i as varchar(2)));
SET @field = 'CAST([' + @column + '] as varchar(200)),';
SET @sql = @sql + @field;
SET @i = @i + 1;
END
SET @column = (SELECT top 1 column_name from ##columnNames where position = @fieldct);
SET @field = 'CAST([' + @column + '] as varchar(200)) FROM ' + @data_source;
SET @sql = @sql + @field; --@sql now contains the SQL statement that will insert data from @data_source into ##columnPivot
--execute @sql to insert into ##columnPivot the data from @data_source table
EXEC master.sys.sp_executesql @sql;
--format the output
IF OBJECT_ID ('tempdb..#columns') IS not null DROP TABLE #columns;
--use a copy of ##columnNames, because next steps delete from this table, and ##columnNames data is needed below. Does not need to be a global temp.
SELECT *
into #columns
from ##columnNames
order by position;
SET @fieldct = (SELECT count(*) from #columns);
SET @i = 1;
--create the header row for the table containing column names from the @data_source
WHILE @i <= @fieldct
BEGIN
SET @field = (SELECT top 1 column_name from #columns order by position);
SET @html = @html + '<td bgcolor="#dedede"><b>' + @field + '</b></td>';
SET @i = @i + 1;
DELETE from #columns where column_name = @field;
END
SET @html = '<tr>' + @html + '</tr>'; --now @html contains the header row of the output table
--populate ##columnPivot by working through the data row by row.
ALTER table ##columnPivot add id_key int identity;
DECLARE
@j int = 1,
@fieldcnt int,
@cell varchar(100),
@row varchar(500) = '';
SET @i = 1;
SET @fieldcnt = (SELECT count(*) from ##columnNames);
SET @rcd_cnt = (SELECT count(*) from ##columnPivot);
WHILE @i <= @rcd_cnt --this loop executes one time for each row of data
BEGIN
SET @j = 1;
WHILE @j <= @fieldcnt --this loop executes one time for each column (cell) of data
BEGIN
SET @sql = 'SELECT @value = f' + cast (@j as varchar(2)) + ' from ##columnPivot where id_key = ' + cast (@i as varchar(2));
EXEC master.sys.sp_executesql @sql, N'@value varchar(200) OUTPUT', @value OUTPUT;
SET @cell = '<td>' + ISNULL (@value, '<br>') + '</td>'; --need to use <br> if the cell is empty
SET @row = @row + @cell;
SET @j = @j + 1;
END
SET @row = '<tr>' + @row + '</tr>';
SET @html = @html + @row;
SET @row = '';
DELETE from ##columnPivot where id_key = cast (@i as varchar(2));
SET @i = @i + 1;
END
SET @tableHTML = '<table border="1" cellspacing="0" cellpadding="5">' + @html + '</table><br>';
END
Tenga en cuenta que estoy invocando el procedimiento "DataSourceCheck" para determinar que el parámetro @data_source contiene el nombre de una tabla válida. DataSourceCheck no tiene que ser un procedimiento separado: el SQL podría incluirse directamente en el procedimiento HtmlTable, pero lo mantengo separado para modularidad y reutilización.
Ejemplo de uso del procedimiento DataSourceCheck
CREATE table ##foo (bar1 int, bar2 varchar(20), bar3 datetime)
INSERT into ##foo values (1, 'Abcdef', getdate())
INSERT into ##foo values (2, 'Ghijkl', '05/05/15')
DECLARE @table varchar(200), @db varchar(50)
EXEC dbo.DataSourceCheck
'##foo',
@db output,
@table output
PRINT @db
PRINT @Table
Salida
tempdb
##foo
Ahora suelte la tabla y vea qué sucede:
DROP table ##foo
DECLARE @table varchar(200), @db varchar(50)
EXEC dbo.DataSourceCheck
'##foo',
@db output,
@table output
PRINT @db
PRINT @Table
Salida
<br>Table ##foo does not exist or is improperly qualified.<br>
Código de procedimiento DataSourceCheck
/*
Author: Leigh Haynes
Date: February 2015
Notes: Called by HtmlTable and CreateCsvFile to check validity of data source that is going to turn into an HTML table or a CSV file.
*/
CREATE PROCEDURE [dbo].[DataSourceCheck]
@dataSource varchar (100) = NULL,
@db varchar(50) = NULL output,
@table varchar(100) = NULL output
AS
BEGIN
DECLARE
@buffer varchar(100),
@object varchar(100),
@objectId bigint,
@schema varchar(50),
@rcd_cnt int,
@tableHtml varchar(200),
@sql nvarchar(1000)
SET @buffer = @dataSource;
--cannot accesss a local temp table. Return.
IF SUBSTRING (@buffer, 1, 1) = '#' and SUBSTRING (@buffer, 2, 1) <> '#'
BEGIN
--use LEFT 25 to make sure the local temp table name isn't too long for the @table varchar(100) variable.
SET @table = '<br>Table ' + LEFT (@dataSource, 25) + ' is a local temp table. Must use a global temp or permanent table.<br>';
RETURN;
END;
--set up the object name in the right format so you can check the OBJECT_ID
ELSE IF (SUBSTRING (@buffer, 1, 2) = '##')
BEGIN
SET @db = 'tempdb';
SET @table = @dataSource;
SET @object = @db + '..' + @table; --need to include tempdb so OBJECT_ID finds the temp table
END;
ELSE
BEGIN
--deal with schema
SET @db = SUBSTRING (@buffer, 1, charindex ('.', @buffer) - 1);
SET @buffer = replace (@buffer, @db + '.', '');
IF SUBSTRING (@buffer, 1, 1) = '.'
BEGIN
SET @schema = '..';
SET @buffer = replace (@buffer, '.', '');
END
ELSE
BEGIN
SET @schema = SUBSTRING (@buffer, 1, charindex ('.', (@buffer)) - 1);
SET @buffer = replace (@buffer, @schema + '.', '');
END
SET @table = @buffer;
SET @object = @dataSource;
END;
--does our data source exist? Check the object_id. If object does not exist, return.
SET @objectId = OBJECT_ID (@object, 'U');
IF @objectId is NULL
BEGIN
SET @db = NULL;
SET @table = '<br>Table ' + @dataSource + ' does not exist or is improperly qualified.<br>';
RETURN;
END;
--we have a valid data source. Check that it has rows and notify if empty.
SET @sql = 'SELECT @rcd_cnt = count(*) from ' + @dataSource;
EXEC master.sys.sp_executesql @sql, N'@rcd_cnt int OUTPUT', @rcd_cnt OUTPUT;
IF @rcd_cnt = 0
BEGIN
SET @db = NULL;
SET @table = '<br>Table ' + @dataSource + ' is empty.<br>';
RETURN;
END;
END
También tengo una versión de HtmlTable que crea un archivo CSV a partir de una tabla (en lugar de una tabla HTML).
