Understanding SQL’s NUMERIC and DECIMAL Data Types
When it comes to working with numbers in SQL, the two data types that come to mind are NUMERIC and DECIMAL. Both data types come in handy when dealing with tasks that require precise and accurate calculations.
In this article, we will explore the differences between NUMERIC and DECIMAL while also discussing their syntax and definition in SQL.
Difference between NUMERIC and DECIMAL
Both NUMERIC and DECIMAL data types are considered “exact” arithmetic data types. This means that the values stored in these data types are not subject to approximation.
The key difference between these two data types lies in how they store the data. NUMERIC data type stores exact values up to a specified precision and scale.
Precision refers to the total number of digits that can be stored in the number, while scale refers to the number of digits to the right of the decimal point. For example, the NUMERIC data type with a precision of 6 and scale of 2 can store any number between -9999.99 and 9999.99.
DECIMAL, on the other hand, also stores exact values up to a specified precision and scale, but it does so in a more flexible manner. DECIMAL has the same precision and scale limitations as NUMERIC but allows for more flexibility in the placement of the decimal point.
This means that a DECIMAL value of 1234.5678 with a precision of 6 and a scale of 4 can be stored, while a NUMERIC value of the same precision and scale cannot.
Precision and Scale in NUMERIC and DECIMAL
1. Precision
As mentioned earlier, precision and scale are critical components of the NUMERIC and DECIMAL data types. Precision determines the number of significant digits that can be stored in a number.
A higher precision means that you can store more significant digits.
2. Scale
The scale, meanwhile, determines the number of digits to the right of the decimal point.
A higher scale means that there are more digits to the right of the decimal point. In general, the maximum size of a NUMERIC or DECIMAL value depends on the precision and scale.
For example, a NUMERIC(10,2) value can store a maximum of 8 digits to the left of the decimal point and 2 digits to the right of the decimal point. Similarly, a DECIMAL(10,2) value can store a maximum of 8 digits to the left of the decimal point and 2 digits to the right of the decimal point.
Strictness of NUMERIC and Flexibility of DECIMAL
One other difference between NUMERIC and DECIMAL is the strictness versus flexibility of their syntax. NUMERIC has a strict syntax and does not allow for variations in formatting.
For instance, NUMERIC(10,2) and NUMERIC(10,3) are entirely different data types, as they have different scales. NUMERIC values must always be specified with their precise precision and scale values.
DECIMAL, on the other hand, has a more flexible syntax. While the precision and scale values must be specified, you can also use alternative syntax forms.
You can use DECIMAL(precision, scale), DEC(precision, scale), or NUMERIC(precision, scale), which all have the same meaning. DECIMAL also allows for different scales between operations, which makes it more flexible than NUMERIC.
Syntax and Definition of NUMERIC and DECIMAL in SQL
Knowing the proper syntax and definition of NUMERIC and DECIMAL in SQL is essential to successfully using these data types in your programs.
1. Syntax and Definition of NUMERIC
To declare a NUMERIC data type in SQL, you must use the following syntax:
NUMERIC (precision, scale)The precision specifies the maximum number of digits that can be stored in the number, while the scale specifies the number of digits to store after the decimal point. For example, if you want to declare a column to store prices with a maximum of 10 digits and 2 decimal places, you would use the following SQL code:
CREATE TABLE products(
id INT PRIMARY KEY,
name VARCHAR(50),
price NUMERIC(10,2)
);2. Syntax and Definition of DECIMAL
The syntax for declaring a DECIMAL data type in SQL is similar to that of NUMERIC. Here is the syntax:
DECIMAL(precision, scale)The precision value specifies the total number of digits that can be stored in the number, while the scale value specifies the number of digits to the right of the decimal point.
For example, if you want to declare a column to store percentages with a maximum of 6 digits and 2 decimal places, you would use the following SQL code:
CREATE TABLE sales(
id INT PRIMARY KEY,
product VARCHAR(50),
sales_percentage DECIMAL(6,2)
);Conclusion
In conclusion, the NUMERIC and DECIMAL data types in SQL are useful tools for handling exact arithmetic in your programs. While they’re often used interchangeably, there are a few key differences between them.
NUMERIC is strict in its syntax and the position of the decimal point, while DECIMAL is more flexible. Both data types require careful consideration of the precision and scale values to avoid data loss or truncation.
By understanding these differences and knowing the proper syntax, you can take full advantage of NUMERIC and DECIMAL in your SQL programs.
Differences between DECIMAL and NUMERIC in Common SQL Dialects
When it comes to working with data types in SQL, the two most commonly used exact numeric data types are DECIMAL and NUMERIC. While they are often used interchangeably, it is important to understand the differences between the two, particularly in different SQL dialects.
In this article, we will explore the differences between DECIMAL and NUMERIC in some of the most common SQL dialects, including Oracle, PostgreSQL, T-SQL, MySQL, SQLite, and Firebird.
1. DECIMAL vs. NUMBER in Oracle
While Oracle does not have a NUMERIC data type, it has a NUMBER data type that can be used in its place. In Oracle, the NUMBER data type can be defined as:
NUMBER(p,s)where “p” is the precision and “s” is the scale.
The default value of precision in Oracle is 38, and the default value for scale is 0.
2. DECIMAL vs. NUMERIC in PostgreSQL
In PostgreSQL, the DECIMAL and NUMERIC data types are interchangeable, and both have the same meaning. They can be defined as:
DECIMAL(p,s)
NUMERIC(p,s)where “p” is the precision and “s” is the scale.
3. DECIMAL vs. NUMERIC in T-SQL
In T-SQL, the DECIMAL and NUMERIC data types are also interchangeable and are defined as:
DECIMAL(p,s)
NUMERIC(p,s)where “p” is the precision and “s” is the scale.
It is worth noting that T-SQL allows for an additional parameter to be specified for the data type, representing the number of bytes used for storage. For example, the maximum storage size for DECIMAL(10,2) could be defined as DECIMAL(10,2,8) to allocate 8 bytes for storage.
4. Implementation of NUMERIC as DECIMAL in MySQL
In MySQL, the NUMERIC data type is implemented as DECIMAL and is defined as:
DECIMAL(p,s)where “p” is the precision and “s” is the scale. This is because MySQL has historically used DECIMAL instead of NUMERIC, and even though the NUMERIC data type is present in MySQL, it is simply an alias for the DECIMAL data type.
5. Treatment of DECIMAL as NUMERIC in SQLite
In SQLite, the DECIMAL data type is not supported. Instead, decimal values are stored as NUMERIC with an optional scale.
However, the NUMERIC data type in SQLite has a maximum precision of 15 digits, and the scale can only be positive.
6. NUMERIC and DECIMAL Differences in Firebird
In Firebird, DECIMAL and NUMERIC are interchangeable, and both have the same meaning. They can be defined as:
DECIMAL(p,s)
NUMERIC(p,s)where “p” is the precision and “s” is the scale.
It is worth noting that Firebird uses a slightly different implementation of the DECIMAL and NUMERIC data types compared to other SQL dialects.
Learning More About SQL Data Types
SQL data types can be complex and difficult to master, especially for beginners. Fortunately, there are many resources available to help you learn more about SQL data types and how to use them effectively.
1. Comprehensive SQL Course for Beginners
For beginners, a comprehensive SQL course can be extremely helpful. One example of a great SQL course for beginners is the “SQL A to Z learning path” offered by datacamp.com.
This course covers everything from the basics of SQL to more advanced topics like working with advanced functions and writing complex queries. It also teaches specific data types, including DECIMAL and NUMERIC, with a focus on how they work in different SQL dialects.
2. Exploring SQL Numeric Data Types
To learn more about specific numeric data types like DECIMAL and NUMERIC, it can be helpful to explore examples and practice working with them in SQL queries. There are many resources available online, including SQL tutorials, documentation, and online communities, where you can find a wealth of information and guidance.
By understanding the differences between DECIMAL and NUMERIC in different SQL dialects, and by practicing with SQL data types, you can become more confident and proficient in working with numeric data in SQL. In summary, understanding the differences between DECIMAL and NUMERIC in various SQL dialects is essential when working with numeric data in SQL programming.
DECIMAL and NUMERIC can be interchangeable in some dialects and have slightly different implementations in others. Knowing the correct syntax and definition in each dialect can prevent errors and lead to more efficient and accurate programming.
Learning SQL data types, such as DECIMAL and NUMERIC, through comprehensive courses and practice can lead to greater proficiency and confidence in using them in your programs. Overall, taking the time to understand the nuances of DECIMAL and NUMERIC in SQL dialects can lead to more effective programming.