fox-manager-2.0-bpa:1.-общая-информация:тонкие-настройки-подключения-к-базе-данных
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fox-manager-2.0-bpa:1.-общая-информация:тонкие-настройки-подключения-к-базе-данных [2020/06/10 23:24] – erazor | fox-manager-2.0-bpa:1.-общая-информация:тонкие-настройки-подключения-к-базе-данных [2021/07/08 20:20] – [Проблемы при одновременном доступе к базе SQLite] erazor | ||
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+ | ===== Проблемы при одновременном доступе к базе SQLite ===== | ||
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+ | База данных SQLite является файловой и рекомендуется для работы одного пользователя, | ||
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+ | * BusyTimeout = 5000 | ||
+ | * LockingMode = lmNormal | ||
+ | * Synchronous = smExtra | ||
===== Проблемы при подключении к базе MySQL 8.x ===== | ===== Проблемы при подключении к базе MySQL 8.x ===== | ||
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|ASCIIDataBase|Enables or disables ASCII support. The default value is False. Note:For this option usage set the UseUnicode option to false.| | |ASCIIDataBase|Enables or disables ASCII support. The default value is False. Note:For this option usage set the UseUnicode option to false.| | ||
|BusyTimeout|Use the ClientLibrary option to set or get the timeout of waiting for locked resource (database or table). If resource is not unlocked during the time specified in BusyTimeout, | |BusyTimeout|Use the ClientLibrary option to set or get the timeout of waiting for locked resource (database or table). If resource is not unlocked during the time specified in BusyTimeout, | ||
+ | |CipherLicense|Holds a license key for SQLCipher Commercial Edition. Note that SQLCipher is not supported in the Direct mode.| | ||
+ | |ConnectMode|The connection mode. **cmDefault** - The default value. The database is opened for reading and writing. Corresponds to the SQLite default behavior. **cmReadWrite** - The database is opened for reading and writing. **cmReadOnly** - The database is opened in read-only mode.| | ||
|ClientLibrary|Use the ClientLibrary option to set or get the client library location.| | |ClientLibrary|Use the ClientLibrary option to set or get the client library location.| | ||
|DateFormat|Defines the format for storing dates in the database. If it is not specified, the default yyyy-mm-dd format will be used. | | |DateFormat|Defines the format for storing dates in the database. If it is not specified, the default yyyy-mm-dd format will be used. | | ||
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|ForegnKeys|Enables or disables the enforcement of foreign key constraints. Foreign key constraints are disabled by default in SQLite, so this option can be used to force enabling or disabling them by the application. Default value of this option is True.| | |ForegnKeys|Enables or disables the enforcement of foreign key constraints. Foreign key constraints are disabled by default in SQLite, so this option can be used to force enabling or disabling them by the application. Default value of this option is True.| | ||
|ForceCreateDatabase|Used to force TLiteConnection to create a new database before opening a connection, if the database does not exist.| | |ForceCreateDatabase|Used to force TLiteConnection to create a new database before opening a connection, if the database does not exist.| | ||
+ | |JournalMode|The journal mode. **jmDelete** - The rollback journal is deleted at the conclusion of each transaction. **jmTruncate** - The rollback journal is stored in volatile RAM. It reduces disk I/O, but decreases database safety and integrity. If the application using SQLite crashes in the middle of a transaction, | ||
+ | |LockingMode|The database locking mode. **lmExclusive** - The database connection never releases file locks. The first time the database is read or written in this mode, a shared lock is obtained and held. Use this mode if you want to prevent other processes from accessing the database file, reduce the number of filesystem operations, or access WAL databases without using the shared memory. **lmNormal** - The database connection unlocks the database file at the conclusion of each read or write transaction.| | ||
+ | |NativeDate|If the option is set to True, the date and time values will be stored in the database in the native SQLite format, and when retrieved, they will be converted to the TDateTime type. If set to False, no conversion to the TDateTime type will be made. The default value is True.| | ||
|ReadUncommitted|Enables or disables Read-Uncommitted isolation mode. A database connection in read-uncommitted mode does not attempt to obtain read-locks before reading from database tables as described above. This can lead to inconsistent query results if another database connection modifies a table while it is being read, but it also means that a read-transaction opened by a connection in read-uncommitted mode can neither block nor be blocked by any other connection. Default value of this option is False. | |ReadUncommitted|Enables or disables Read-Uncommitted isolation mode. A database connection in read-uncommitted mode does not attempt to obtain read-locks before reading from database tables as described above. This can lead to inconsistent query results if another database connection modifies a table while it is being read, but it also means that a read-transaction opened by a connection in read-uncommitted mode can neither block nor be blocked by any other connection. Default value of this option is False. | ||
+ | |Synchronous|The database synchronization mode when writing to disk. **smOff** - The database engine continues without syncing after handing data off to the operating system. If the application running SQLite crashes, the data will safe, unless the operating system crashes or the computer loses power before data has been written to disk, in which case the database might become corrupted. This is the fastest mode. **smNormal** - The database engine still syncs at the most critical moments, but less often than in the FULL mode. The Normal mode is faster than the Full mode. When using the WAL mode (and probably the DELETE mode) with synchronous=NORMAL, | ||
|TimeFormat|Defines the format for storing time in the database. If it is not specified, the default hh24:mi:ss format will be used. | | |TimeFormat|Defines the format for storing time in the database. If it is not specified, the default hh24:mi:ss format will be used. | | ||
- | |UseUnicode|Enables or disables Unicode support. Affects character data fetched from the server. When set to True, all character data is stored as WideStrings, and TStringField is replaced by TWideStringFiled.| | + | |UseUnicode|Enables or disables Unicode support. When set to True, all character data is stored as WideString, and TStringField is used instead of TWideStringField. The default value is False.| |
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fox-manager-2.0-bpa/1.-общая-информация/тонкие-настройки-подключения-к-базе-данных.txt · Последнее изменение: 2024/05/12 19:35 — 127.0.0.1