Table Column Types for Approximate Numbers

Describes 3 types of table columns to store approximate numbers: FLOAT, REAL and DOUBLE PRECISION.

There are 3 types of table columns to store approximate numbers: FLOAT, REAL and DOUBLE PRECISION.

"FLOAT(precision)" - Approximate numeric value with specified precision or higher. No scale is specified for FLOAT.

"REAL" - Approximate numeric value with no scale. Precision is defined by the implementation.

"DOUBLE PRECISION" - Approximate numeric value with no scale. Precision is defined by the implementation and should be higher than REAL.

Examples of approximate number column types, ApproximateNumberColumns.sql:

```-- ApproximateNumberColumns.sql
--
CREATE TABLE ApproximateNumber (
Line VARCHAR(8),
X FLOAT(8), -- (precision)
Y REAL,
Z DOUBLE PRECISION
);
INSERT INTO ApproximateNumber VALUES (
'1',
1.11,
2.22,
3.33
);
INSERT INTO ApproximateNumber VALUES (
'2',
11.1111,
22.2222,
33.3333
);
INSERT INTO ApproximateNumber VALUES (
'3',
111.111111,
222.222222,
333.333333
);
INSERT INTO ApproximateNumber VALUES (
'4',
2/3,
2/3,
2/3
);
SELECT * FROM ApproximateNumber;
DROP TABLE ApproximateNumber;
```

Output:

```Line    X       Y       Z
1       1.11    2.22    3.33
2       11.1111 22.2222 33.3333
3       111.111 222.222222      333.333333
4       0.666667        0.666666666666667       0.666666666666667
```

Note that:

• Line 3 tells us that FLOAT(8) can only take 6 digits, if not enough space, extra fractional digits will be rounded up or down.
• Line 4 tells us that REAL and DOUBLE PRECISION are having the same precision.