Hi, Allen.
I am trying to compare 2 fields with different data types (text and
single),
but I cannot the SQL type-conversion functions that works in SQL Server
aren't recognised.
T-SQL syntax doesn't work the same (or often not at all) in Jet SQL or in
Access VBA, just like it won't work in PL/SQL, SQL*Plus, or MySQL. It's a
different dialect of SQL that works in SQL Server, but can't be expected to
be used with other database products.
Is this a profound shortcoming of Access 2003, or is the
information I want just carefully hidden or omitted from Help?
From Access 2003 online help:
Type Conversion Functions
Each function coerces an expression to a specific data type.
Syntax
CBool(expression)
CByte(expression)
CCur(expression)
CDate(expression)
CDbl(expression)
CDec(expression)
CInt(expression)
CLng(expression)
CSng(expression)
CStr(expression)
CVar(expression)
The required expression argument is any string expression or numeric
expression.
Return Types
The function name determines the return type as shown in the following:
Function Return Type Range for expression argument
CBool Boolean Any valid string or numeric expression.
CByte Byte 0 to 255.
CCur Currency -922,337,203,685,477.5808 to 922,337,203,685,477.5807.
CDate Date Any valid date expression.
CDbl Double -1.79769313486231E308 to
-4.94065645841247E-324 for negative values; 4.94065645841247E-324 to
1.79769313486232E308 for positive values.
CDec Decimal +/-79,228,162,514,264,337,593,543,950,335 for zero-scaled
numbers, that is, numbers with no decimal places. For numbers with 28
decimal places, the range is
+/-7.9228162514264337593543950335. The smallest possible non-zero number is
0.0000000000000000000000000001.
CInt Integer -32,768 to 32,767; fractions are rounded.
CLng Long -2,147,483,648 to 2,147,483,647; fractions are rounded.
CSng Single -3.402823E38 to -1.401298E-45 for negative values; 1.401298E-45
to 3.402823E38 for positive values.
CStr String Returns for CStr depend on the expression argument.
CVar Variant Same range as Double for numerics. Same range as String for
non-numerics.
Remarks
If the expression passed to the function is outside the range of the data
type being converted to, an error occurs.
In general, you can document your code using the data-type conversion
functions to show that the result of some operation should be expressed as a
particular data type rather than the default data type. For example, use
CCur to force currency arithmetic in cases where single-precision,
double-precision, or integer arithmetic normally would occur.
You should use the data-type conversion functions instead of Val to provide
internationally aware conversions from one data type to another. For
example, when you use CCur, different decimal separators, different thousand
separators, and various currency options are properly recognized depending
on the locale setting of your computer.
When the fractional part is exactly 0.5, CInt and CLng always round it to
the nearest even number. For example, 0.5 rounds to 0, and 1.5 rounds to 2.
CInt and CLng differ from the Fix and Int functions, which truncate, rather
than round, the fractional part of a number. Also, Fix and Int always return
a value of the same type as is passed in.
Use the IsDate function to determine if date can be converted to a date or
time. CDate recognizes date literals and time literals as well as some
numbers that fall within the range of acceptable dates. When converting a
number to a date, the whole number portion is converted to a date. Any
fractional part of the number is converted to a time of day, starting at
midnight.
CDate recognizes date formats according to the locale setting of your
system. The correct order of day, month, and year may not be determined if
it is provided in a format other than one of the recognized date settings.
In addition, a long date format is not recognized if it also contains the
day-of-the-week string.
A CVDate function is also provided for compatibility with previous versions
of Visual Basic. The syntax of the CVDate function is identical to the CDate
function, however, CVDate returns a Variant whose subtype is Date instead of
an actual Date type. Since there is now an intrinsic Date type, there is no
further need for CVDate. The same effect can be achieved by converting an
expression to a Date, and then assigning it to a Variant. This technique is
consistent with the conversion of all other intrinsic types to their
equivalent Variant subtypes.
Note The CDec function does not return a discrete data type; instead, it
always returns a Variant whose value has been converted to a Decimal
subtype.
HTH.
Gunny
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