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All the data in a column must be of the same type. Specify
the data type for each column when you create a table or when you
add a column to an existing table. The ALLBASE/SQL data types and
the values you can specify for data of each type are shown in Table 7-1 “ALLBASE/SQL Data Types” Table 7-1 ALLBASE/SQL Data Types | Group | Data Type | Description |
|---|
| Alpha-
numeric | CHAR[ACTER][(n)] | String of fixed length n, where n is an integer from 1 to 3996 bytes. The default size
is CHAR (1). The keyword CHARACTER is a synonym
for CHAR. | | | VARCHAR(n) | String of variable length no greater than n, where n must be an integer from 1 to 3996 bytes. | | Numeric | DEC[IMAL][(p[,s])] NUMERIC[(p[,s])] | Fixed-point packed decimal
number with a precision (maximum number of
digits excluding sign and decimal point) no greater than p, where p is 1 through 27, and a scale (number
of digits to the right of the decimal) of s, where s is from 0 through p. E (exponential) and L (Pascal longreal) notation
are not allowed in the specification of a decimal value. Operations
on data of type DECIMAL are often much more precise than operations
on data of type FLOAT. The default for NUMERIC and DECIMAL
types is DECIMAL (27,0). DEC and NUMERIC are synonyms for DECIMAL. | | | FLOAT[(p)] or DOUBLE PRECISION | Long (64-bit) floating point
number. This is an approximate numeric value consisting of an exponent
and a mantissa. The precision, p, is a positive integer that specifies the number
of significant binary digits in the mantissa. The value of p can be from 25 to 53. The default is 53. The
range of negative numbers that can be represented is -1.79769313486230E+308
to -2.22507385850721E-308. The range of positive
numbers that can be represented is 2.22507385850721E-308
to 1.79769313486230E+308. E (exponential) or L (Pascal longreal)
notation can be used to specify FLOAT values. DOUBLE
PRECISION is a synonym for FLOAT(53). | | | FLOAT(p) or REAL | Short (32-bit) floating
point number. This is an approximate numeric value consisting of
an exponent and a mantissa. The precision, p, is a positive integer that specifies the number
of significant binary digits in the mantissa. The value of p can be from 1 to 24. The default (using REAL) is
24. The range of negative numbers that can be represented is -3.402823E+38
to -1.175495E-38. The range of positive numbers
that can be represented is 3.402823E+38 to 1.175495E-38. REAL
is a synonym for FLOAT (24). | | | INT[EGER] | Integer in the range -2147483648
(-231) το 2147483647 (231-1). ΙΝΤ ισ α σψνονψµ φορ ΙΝΤΕΓΕΡ. | | | SMALLINT | Integer in the range -32768 (-215) το 32767
(215-1). | | Date/Time | DATE | String of form 'YYYY-MM-DD', where
YYYY represents the calendar year, MM is the month, and DD is the
day of the month. DATE is in the range from '0000-01-01' to '9999-12-31'. | | | TIME | String of the form 'HH:MI:SS:
where HH represents hours, MI is minutes, and SS is seconds. TIME
is in the range from '00:00:00' to '23:59:59'. | | | DATETIME | String of the form 'YYYY-MM-DD
HH:MI:SS.FFF', where YYYY
represents the calendar year, MM is the month, DD is the day, HH
the hour, MI the minute, SS the second, and FFF thousandths of a
second. The range is from '000-01-01 00:00:00.000' to '9999-12-31
23:59:59.999'. | | | INTERVAL | String of the form 'DDDDDDD HH:MI:SS.FFF',
where DDDDDDD is a number of days, HH a number of hours, MI a number
of minutes, SS a number of seconds, and FFF a number of thousandths
of a second. The range is from '0 00:00:00.000' to '3652436 23:59:59.999'. | | Binary | BINARY(n) | Binary string of fixed length n, where n is an integer from 1 to 3996 bytes. Each byte stores
2 hexadecimal digits. | | | VARBINARY(n) | Binary string of variable length
no greater than n, where n is an integer from 1 to 3996 bytes. Each byte stores
2 hexadecimal digits. | | | LONG BINARY(n) | Binary string of fixed length n, where n is an integer from 1 to (231-1) βψτ[epsiv]σ. | | | LONG VARBINARY(n) | Binary string of variable length no greater
than n, where n is an integer from 1 to (231-1) βψτ[epsiv]σ. |
Your choice of data types can affect the following: How values are used in expressions.
Some operations can be performed only with data of a certain type.
For example, arithmetic operations are limited to numeric and date/time
data types, such as INTEGER, SMALLINT, FLOAT, DECIMAL, DATE, TIME,
DATETIME, or INTERVAL. Pattern matching with the LIKE predicate
can be performed only with string data, that is, data of types CHAR
or VARCHAR. The result of operations combining data of different
types. When comparisons and expressions combining data of different
but compatible types are evaluated, ALLBASE/SQL performs type conversion,
as described later in this chapter. How values are transferred programmatically. When
data is transferred between ALLBASE/SQL and an application program
in host variables, ALLBASE/SQL uses the data type equivalencies
described in the ALLBASE/SQL application programming guides.
Table 7-2 “Data Type Storage Requirements” contains the storage requirements
of the various data types. Table 7-2 Data Type Storage Requirements | Type | Storage Required |
|---|
| CHAR (n) | n bytes (where n must be an
integer from 1 to 3996) | | VARCHAR (n) | n bytes (where n must be an
integer from 1 to 3996) | | DECIMAL (p[,s]) | 4 bytes (where p <=
7) or 8 bytes (where 7 < p <= 15) or 12 bytes
(where 15 < p <= 23) or 16 bytes (where p > 23) | | FLOAT | 8 bytes | | REAL | 4 bytes | | INTEGER | 4 bytes. Integer values less
than -2147483648 (-2**31) or larger than 2147483647 (2**31 - 1)
up to 15 digits long are stored as decimals with a precision of
15 and a scale of 0, i.e., equivalent to DECIMAL (15,0) | | SMALLINT | 2 bytes | | DATE | 16 bytes | | TIME | 16 bytes | | DATETIME | 16 bytes | | INTERVAL | 16 bytes | | BINARY (n) | n bytes (where n must be an
integer from 1 to 3996) | | VARBINARY (n) | n bytes (where n must be an
integer from 1 to 3996) | | LONG BINARY (n) | n bytes (where n must be an
integer from 1 to 231 - 1) | | LONG VARBINARY (n) | n bytes (where n must be an
integer from 1 to 231 - 1) |
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