Today I had the opportunity to debug a system with a client. I have to confess it took a while to figure out the bug, but here it is
SELECT COUNT(*) OfflineData
Do you see the bug?
Yes, there should be a FROM clause before the table name. Without the from clause, SQL Server treats the name as an alias for the count column. And what do the COUNT always return in this case?
It returns 1.
So the bug had a severe implication. Now I now it's easy to forget to write a FROM in your query. How can we avoid these stupid mistakes?
An...
CREATE FUNCTION dbo.fnConvertUtf8Ansi
(
@Source VARCHAR(MAX)
)
RETURNS VARCHAR(MAX)
AS
BEGIN
DECLARE @Value SMALLINT = 160,
@Utf8 CHAR(2),
@Ansi CHAR(1)
IF @Source NOT LIKE '%[ÂÃ]%'
RETURN @Source
WHILE @Value <= 255
BEGIN
SELECT @Utf8 = CASE
WHEN @Value BETWEEN 160 AND 191 THEN CHAR(194) + CHAR(@Value)
WHEN @Value BETWEEN 192 AND 255 THEN CHAR(195) + CHAR(@Value - 64)
ELSE NULL
END,
@Ansi = CHAR(@Value)
WHILE CHARINDEX(@Source, @Utf8) > 0
SET @Source = REPLACE(@Source, @Utf8, @Ansi)
SET @Value += 1
END
RETURN @Source
END