C. SQLite
介绍
This is an extension for the SQLite Embeddable SQL Database Engine. SQLite is a C library that implements an embeddable SQL database engine. Programs that link with the SQLite library can have SQL database access without running a separate RDBMS process.
SQLite is not a client library used to connect to a big database server. SQLite is the server. The SQLite library reads and writes directly to and from the database files on disk.
注: For further information see the SQLite Website (http://sqlite.org/).
Installation
Read the INSTALL file, which comes with the package. Or just use the PEAR installer with "pear install sqlite". SQLite itself is already included, You do not need to install any additional software.
Windows users may download the DLL version of the SQLite extension here: (php_sqlite.dll).
需求
In order to have these functions available, you must compile PHP with SQLite support, or load the SQLite extension dynamically from your php.ini.
资源类型
There are two resources used in the SQLite Interface. The first one is the database connection, the second one the result set.
Predefined Constants
The functions sqlite_fetch_array() and sqlite_current() use a constant for the different types of result arrays. The following constants are defined:
表格 1. SQLite fetch constants
| constant | meaning |
|---|---|
| SQLITE_ASSOC | Columns are returned into the array having the fieldname as the array index. |
| SQLITE_BOTH | Columns are returned into the array having both a numerical index and the fieldname as the array index. |
| SQLITE_NUM | Columns are returned into the array having a numerical index to the fields. This index starts with 0, the first field in the result. |
运行时配置
这些函数的行为受到全局配置文件 php.ini 的影响。
For further details and definition of the PHP_INI_* constants see ini_set().
以下是该配置选项的简要解释。
- sqlite.assoc_case int
Whether to use mixed case (0), upper case (1) or lower case (2) hash indexes.
This option is primarily useful when you need compatibility with other database systems, where the names of the columns are always returned as uppercase or lowercase, regardless of the case of the actual field names in the database schema.
The SQLite library returns the column names in their natural case (that matches the case you used in your schema). When sqlite.assoc_case is set to 0 the natural case will be preserved. When it is set to 1 or 2, PHP will apply case folding on the hash keys to upper- or lower-case the keys, respectively.
Use of this option incurs a slight performance penalty, but is MUCH faster than performing the case folding yourself using PHP script.
- 目录
- sqlite_array_query -- Execute a query against a given database and returns an array.
- sqlite_busy_timeout -- Set busy timeout duration, or disable busy handlers.
- sqlite_changes -- Returns the number of rows that were changed by the most recent SQL statement.
- sqlite_close -- Closes an open SQLite database.
- sqlite_column -- Fetches a column from the current row of a result set.
- sqlite_create_aggregate -- Register an aggregating UDF for use in SQL statements.
- sqlite_create_function -- Registers a "regular" User Defined Function for use in SQL statements.
- sqlite_current -- Fetches the current row from a result set as an array.
- sqlite_error_string -- Returns the textual description of an error code.
- sqlite_escape_string -- Escapes a string for use as a query parameter
- sqlite_fetch_array -- Fetches the next row from a result set as an array.
- sqlite_fetch_single -- Fetches the first column of a result set as a string.
- sqlite_fetch_string -- Alias of sqlite_fetch_single()
- sqlite_field_name -- Returns the name of a particular field.
- sqlite_has_more -- Returns whether or not more rows are available.
- sqlite_last_error -- Returns the error code of the last error for a database.
- sqlite_last_insert_rowid -- Returns the rowid of the most recently inserted row.
- sqlite_libencoding -- Returns the encoding of the linked SQLite library.
- sqlite_libversion -- Returns the version of the linked SQLite library.
- sqlite_next -- Seek to the next row number.
- sqlite_num_fields -- Returns the number of fields in a result set.
- sqlite_num_rows -- Returns the number of rows in a buffered result set.
- sqlite_open -- Opens a SQLite database. Will create the database if it does not exist
- sqlite_popen -- Opens a persistent handle to an SQLite database. Will create the database if it does not exist.
- sqlite_query -- Executes a query against a given database and returns a result handle.
- sqlite_rewind -- Seek to the first row number.
- sqlite_seek -- Seek to a particular row number of a buffered result set.
- sqlite_udf_decode_binary -- Decode binary data passed as parameters to an UDF.
- sqlite_udf_encode_binary -- Encode binary data before returning it from an UDF.
- sqlite_unbuffered_query -- Execute a query that does not prefetch and buffer all data