MySQL Data types
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This document provides an overview of MySQL data types. It discusses that MySQL supports standard SQL data types including numeric, date/time, and string types. Numeric types store integers, decimals, and floating-point numbers. Date/time types store dates, times, and timestamps. String types store text-based data in formats like CHAR, VARCHAR, BLOB and TEXT. Each data type specifies possible values and operations and how data is stored.
MySQL Data types
- 1. Overview of MySQL Data types
- 2. What is a data type? A data type specifies a particular type of data, such as integer, floating-point, Boolean etc……. A data type also specifies the possible values for that type, the operations that can be performed on that type and the way the values of that type are stored
- 3. MySQL data types Supports a number of SQL standard data types in various categories. Has three main categories Numeric types DATE and TIME type String
- 4. MySQL Numeric types MySQL supports all standard SQL numeric data types Include INTEGER SMALLINT DECIMAL NUMERIC
- 5. MySQL Numeric types cont.… Also supports approximate numeric data types FLOAT REAL DOUBLE PRECISION
- 6. Integer types SQL standard integer types INTEGER(or INT) and SMALLINT are supported by MySQL. Also supports the integer types; TINYINT MEDIUMINT BIGINT
- 7. Required storage and range Type Length in bytes Minimum Value (Signed) Max Val (Signed) Min Val (Unsigned) Max Val (Unsigned) TINYINT 1 -128 127 0 255 SMALLINT 2 -32768 32767 0 65535 MEDIUMINT 3 -8388608 8388607 0 16777215 INT 4 -2147483648 2147483648 0 429497295 BIGINT 8 - 922337203685 4775808 922337203685 4775808 0 184467440737 09551615
- 8. Floating-Point Types The FLOAT and DOUBLE types represent approximate numeric data values. MySQL allows non standard syntax FLOAT(M,D) REAL(M,D) Here values can be stored up to M digits in total where D represent decimal point
- 9. Required storage and range Type Length in byte Minimum value (Signed) Maximum value(Singed) Minimum Value (Unsigned) Maximum Value (Unsigned) FLOAT 4 - 3.402823466E+3 8 -1.175494351E- 38 1.175494351E- 38 3.402823466E+3 DOUBLE 8 - 1.797693134862 3 157E+ 308 - 2.225073858507 20 14E- 308 0, and 2.225073858507 20 14E- 308 1.797693134862 315 7E+ 308
- 10. Fixed-Point Types Used to preserve exact precision For example currency data. DECIMAL and NUMERIC type store exact numeric data values
- 11. More in fixed point type DECIMAL(5,2) be able to store any value with five digits and 2 decimals Value range will be -999.99 to 999.99 DECIMAL(M) is equivalent to DECIMAL(M,0) DECIMAL is equivalent to DECIMAL(M,0) MySQL supports both of these forms
- 12. Represent DATE, TIME, DATETIME, TIMESTAMP and YEAR Each type has range of valid values as well as a zero values. MySQL Date and Time Types
- 13. DATETIME, DATE, and TIMESTAMP Types Types Description Display Format Range DATETIME Use when you need values containing both date and time information YYYY-MM-DD HH:MM:SS '1000-01-01 00:00:00' to '9999-12-31 23:59:59'. DATE Use when you need only date information. YYYY-MM-DD '1000-01-01' to '9999- 12-31'. TIMESTAMP Values are converted from the current time zone to UTC while storing, and converted back from UTC to the current time zone when retrieved YYYY-MM-DD HH:MM:SS '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC
- 14. Time Type Fetch and display time value in ‘HH:MM:SS’ or ‘HHH:MM:SS’ format Range : from ‘-838:59:59’ to ‘839:59:59’. MySQL explain abbreviated TIME values with colons as the time of the day. Suppose ’09:10’ means ’09:10:00’ not ’00:09:10’ Two right most digits represent seconds.
- 15. Time Type cont. Fro example we think ‘0910’ and 0910 as meaning 09:10:00, i.e. 10 minutes after 9 o’clock but reality is MySQL understand them as 00:09:10, i.e. 9 minutes and 10 second.!
- 16. Year Type Year type is 1-byte type represent year values. Can be declared as YEAR(2) or YEAR(4) to specify a display width 2 or 4 characters Default width is four characters. YEAR(4) and YEAR(2) have different display format, but have the same range of values. For 2-digt format, MySQL displays only the last two digits; For example, 70 (1970) or 2070
- 17. Year Type cont. We also can specify YEAR values in a variant formats; String length Range 4-digit string ‘1901’ to ‘2155’ 4-digit number 1901 to 2155 1- or 2-digit string ‘0’ to ‘99'. Values in the ranges '0' to '69' and '70' to '99' are converted to YEAR values in the ranges 2000 to 2069 and 1970 to 1999 1- or 2-digit number 1 to 99. Values in the ranges 1 to 69 and 70 to 99 are converted to YEAR values in the ranges 2001 to 2069 and 1970 to 1999.
- 18. String Types The string types: CHAR VARCHAR BINARY VARBINARY BLOB TEXT
- 19. CHAR and VARCHAR Types CHAR and VARCHAR types are similar, but differ in the way they are stored and retrieved. They also differ in maximum length.
- 20. CHAR and VARCHAR Types cont. Type Description Display format Range in characters CHAR Contains non- binary strings. Length is fixed as you declare while creating a table. When stored, they are right-padded with spaces to the specified length Trailing spaces are removed. The length can be any value from 0 to 255. VARCHAR Contains non- binary strings. Columns are variable-length strings As stored. A value from 0 to 255 before MySQL 5.0.3, and 0 to 65,535 in 5.0.3 and later versions
- 21. BINARY and VARBINARY Types Similar to CHAR and VARCHAR But they contain binary strings rather than non binary strings. Type Description Range in bytes BINARY Contains binary strings 0 to 255 VARBINARY Contain binary strings. A value from 0 to 255 before MySQL 5.0.3, and 0 to 65,535 in 5.0.3 and later versions
- 22. BLOB and TEXT types A BLOB is a binary large object that can hold a variable amount of data. Four types of BLOBS (differ only the maximum length) TINYBLOB MEDIUMBLOB LONGBLOB
- 23. BLOB and TEXT types cont. Four TEXT types TINYTEXT TEXT MEDIUMTEXT LONGTEXT Corresponding blob types and text type have the same maximum length
- 24. BLOB and TEXT types cont. Type Description Category Range BLOB Large binary object that containing a variable amount of data. Values are treated as binary strings. You don't need to specify length while creating a column TINYBLOB Maximum length of 255 characters. MEDIUMBLOB Maximum length of 16777215 characters. LONGBLOB Maximum length of 4294967295 characters TEXT Values are treated as character strings having a character set TINYBLOB Maximum length of 255 characters. MEDIUMBLOB Maximum length of 16777215
- 25. Reference http://dev.mysql.com/doc/refman/5.0/en/data-types.html http://www.tutorialspoint.com/mysql/mysql-data-types.htm http://www.webdevelopersnotes.com/tutorials/sql/mysql_database _introduction_mysql_beginners_tutorial.php3