![]() Number of days since noon in Greenwich on NovemB.C. There is no separate class in SQLite databases to store dates and times and is thus stored as TEXT, REAL or INTEGER values. Here, 0 represents FALSE and 1 represents TRUE. In SQLite, Boolean values are stored as integers 0 and 1, since there is no separate storage class for Boolean values in SQLite. In SQLite you can actually store any type of data in any type of column (as the above demonstrates). In SQlite column types are only an indication of the type of data. NUMERIC DECIMAL(10,5) BOOLEAN DATE DATETIME SQlite in regards to column and data types is not typical. INT INTEGER TINYINT SMALLINT MEDIUMINT BIGINT UNSIGNED BIGINT INT2 INT8ĬHARACTER(20) VARCHAR(255) VARYING CHARACTER(255) NCHAR(55) NATIVE CHARACTER(70) NVARCHAR(100) TEXT CLOB Thus there are five different groups of SQLite Affinity and Type Names which are listed below. These names are grouped together and than listed as per their Affinity. Various names for data types can also be used while creating SQLite tables. No preference for one storage class and no persuasion of data from one storage class to other. Same as numeric affinity but forces integer values into floating point representation. Same as numeric affinity with an exception in a cast expression. Stores all data using storage classes NULL, TEXT or BLOB.Ĭontain values using all five storage classes. There are five types of affinity supported by SQLite3 database. The preferred storage class for a column is called its affinity. Stored using the database encoding (utf-8, utf-16be or utf-16le) Stored as an 8-byte IEEE floating point number. These storage classes are listed below:ĭepending on the magnitude of the value, it can be stored in 1, 2, 3, 4, 6, or 8 bytes. ![]() One of the five storage classes that SQLite supports is associated with each stored value in a SQLite database. These data types are divided into various categories, where the value of a data type is not associated with its container but is associated with the value itself. Doubles are stored as 8-byte IEEE, text in the format configured for the database file (UTF-8 by default), and BLOBs are unmodified.A more general dynamic type data type system is used in SQLite to represent the type of data that can be stored and processed and to specify the type of operations that can be performed. On disk, SQLite uses a compact format for integers, depending on their actual value. Sqlite doesn't give you access to the underlying data type, you acess the data through functions like sqlite_column_int, and if the stored data is of a diffent type, it's converted to the requested type. But read the section on 'column affinity' in the datatypes page for the importance of selecting the right types and aliases for the pre-defined types. width' VARCHAR() fields (I know, in practice it can be crossed over), as well as 'no limit' TEXT fields. You can query the actual type of the value stored using sqlite3_column_type. We can define in, using SQLite, both 'fixed max. Yes, your INTEGER affinity column can contain strings. the string is "Hello!"), it is inserted as a string. if you insert a string into a column with INTEGER affinity, it tries to convert that string to an integer. When you insert a value into a column, SQLite tries to convert it to the storage class closest to that affinity.Į.g. To SQLite, it makes no difference whether you specify the column type as INT(1) or INTEGER(8), the resulting affinity will be INTEGER (however, SQLite remembers the actual string you used.). When you create a column, SQLite maps the type you specify to one of these storage classes. it doesn't matter whether an integer is stored as 8 bit or 64 bit if they are integers they add numerically.Ī column has an affinity, which is its preferred storage class. The storage class determines how the value behaves in expresisons etc. SQLite knows distinct data types (including integers of different sizes etc.) They are grouped into storage classes (INTEGER, REAL, TEXT, BLOB and NULL). It can be confusing and weird, though in my experience mostly harmless and sometimes helpful in practice.
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