Storage class of the text is converted to INTEGER or REAL (in order of ] R-12079-51392:[ When text data is inserted into a NUMERIC column, the R-64016-22984:[ A column with NUMERIC affinity may contain values using all five TEXT affinity it is converted into text form before being stored. ] R-54378-38553:[ If numerical data is inserted into a column with R-21926-12440:[ A column with TEXT affinity stores all data using storage classes (Historical note: The "BLOB" type affinity used to be called "NONE".īut that term was easy to confuse with "no affinity" and so it was R-64962-17428:[ Each column in an SQLite 3 database is assigned one of the It is just that some columns, given the choice, will prefer to use Any column can still store any type of data. The important idea here is that the type is recommended, not The type affinity of a column is the recommended type for data stored SQLite supports the concept of "type affinity" on columns. In order to maximize compatibility between SQLite and other databaseĮngines, and so that the example above will work on SQLite as it does Integer 123 and the integer 456 into a string '456' prior to Rigidly-typed database will convert the string '123' into an SQL database engines that use rigid typing will usually try toĪutomatically convert values to the appropriate datatype. INTEGER as Unix Time, the number of seconds sinceĪpplications can choose to store dates and times in any of theseįormats and freely convert between formats using the built-inĭate and time functions.REAL as Julian day numbers, the number of days since.TEXT as ISO8601 strings ("YYYY-MM-DD HH:MM:SS.SSS").Storing dates and times as TEXT, REAL, or INTEGER values: R-48204-18881:[ Instead, the built-in Date And Time Functions of SQLite are capable of SQLite does not have a storage class set aside for storing Really just alternative spellings for the integer literals 1 and 0 SQLite recognizes the keywords "TRUE" and "FALSE",Īs of version 3.23.0 () but those keywords are SQLite does not have a separate Boolean storage class. (INTEGER and REAL) and TEXT during query execution. R-30470-29835:[ Any column in an SQLite version 3 database,Įxcept an INTEGER PRIMARY KEY column, may be used to store a valueĪll values in SQL statements, whether they are literals embedded in SQLĭatabase engine may convert values between numeric storage classes "datatype" and the two terms can be used interchangeably. Processing, they are converted to the most general datatypeĪnd so for the most part, "storage class" is indistinguishable from The INTEGER storage class, for example, includes 7 different integerīut as soon as INTEGER values are read off of disk and into memory for The value is a blob of data, stored exactly asĪ storage class is more general than a datatype. The value is a text string, stored using theĭatabase encoding (UTF-8, UTF-16BE or UTF-16LE).īLOB. The value is a floating point value, stored as The value is a signed integer, stored in 0, 1,Ģ, 3, 4, 6, or 8 bytes depending on the magnitude of the value. That do rigid type enforcement, for developers who prefer that kind of thing.Įach value stored in an SQLite database (or manipulated by theĭatabase engine) has one of the following storage classes: Flexible typing is a feature of SQLite, not a bug.Īs of version 3.37.0 (), SQLite provides STRICT tables It to do things which are not possible in traditional rigidly typedĭatabases. However, the dynamic typing in SQLite allows In the sense that SQL statements that work on statically typed databases The dynamic type system of SQLite is backwardsĬompatible with the more common static type systems of other database engines ![]() ![]() Of a value is associated with the value itself, not with its container. SQLite uses a more general dynamic type system. Of a value is determined by its container - the particular column in Most SQL database engines (every SQL database engine other than SQLite,Īs far as we know) uses static, rigid typing.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |