If the declared type for a column contains any of the strings "REAL", "FLOA", or "DOUB" then the column has REAL affinity. If the declared type for a column contains the string "BLOB" or if no type is specified then the column has affinity NONE. Notice that the type VARCHAR contains the string "CHAR" and is thus assigned TEXT affinity. If the declared type of the column contains any of the strings "CHAR", "CLOB", or "TEXT" then that column has TEXT affinity. Tables may be created in the main database, the temp database, or in any attached database. The database in which the new table is created. If the declared type contains the string "INT" then it is assigned INTEGER affinity. A CREATE TABLE command specifies the following attributes of the new table: The name of the new table. The longer story is that column definitions express a type affinity and SQLite. The affinity of a column is determined by the declared type of the column, according to the following rules in the order shown: sqlite> create table t1 (v1 int, v2 varchar(10)) sqlite> insert into t1. The preferred storage class for a column is called its "affinity".Įach column in an SQLite 3 database is assigned one of the following type affinities: It is just that some columns, given the choice, will prefer to use one storage class over another. Any column can still store any type of data. The important idea here is that the type is recommended, not required. The type affinity of a column is the recommended type for data stored in that column. In order to maximize compatibility between SQLite and other database engines, SQLite supports the concept of "type affinity" on columns. The value is a blob of data, stored exactly as it was input. The value is a text string, stored using the database encoding (UTF-8, UTF-16BE or UTF-16LE).īLOB. The value is a floating point value, stored as an 8-byte IEEE floating point number. The value is a signed integer, stored in 1, 2, 3, 4, 6, or 8 bytes depending on the magnitude of the value. However, the dynamic typing in SQLite allows it to do things which are not possible in traditional rigidly typed databases.Įach value stored in an SQLite database (or manipulated by the database engine) has one of the following storage classes: The dynamic type system of SQLite is backwards compatible with the more common static type systems of other database engines in the sense that SQL statement that work on statically typed databases should work the same way in SQLite. In SQLite, the datatype of a value is associated with the value itself, not with its container. This column may contain values using all five storage classes.īehaves the same as a column with NUMERIC affinity with an exception in a CAST expression.īehaves like a column with NUMERIC affinity except that it forces integer values into floating point representationĪ column with affinity NONE does not prefer one storage class over another and no attempt is made to coerce data from one storage class into another.SQLite uses a general dynamic type system. This column stores all data using storage classes NULL, TEXT or BLOB. SQLite supports the concept of "type affinity" on columns. In SQLite, Boolean values are stored as integers i.e. SQLite does not Provide a separate Boolean storage class. Column Affinity Behavior JavaScript Example. This section comprises the following: SQLite characteristics. The value is a blob of data, stored exactly as it was input. SQLite is a database engine packaged along with the native sdk. Text string, stored using the database encoding (UTF-8, UTF-16BE or UTF-16LE). Signed integer, stored in 1, 2, 3, 4, 6, or 8 bytes depending on the magnitude of the valueĪ floating point value, 8-byte IEEE floating point number. Storage classes Every value which is stored in an SQLite database has one of the following storage classes. In SQLite, the data type of a value is associated with the value itself, not with its container.
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