• Coredata collation (2) – multithreading scheme


    Coredata collation (2) – multithreading scheme Catalog Why multithreading How to use multithreading Multithreading scheme Why multithreading When you get here, you must ask, the function of adding, deleting, modifying and querying has been realized. Why use multithreading well? In fact, core data is Data Persistence technology after all. If the amount of data is […]

  • Coredata arrangement (3) — the use of magic record


    Coredata arrangement (3) — the use of magic record Catalog How to use magicalrecord Crud operation by magicalrecord How to use magicalrecord Magicalrecord encapsulates coredata once, encapsulates complex operations in multi-threaded core data, and provides rich encapsulation methods, with clear and concise code. The magic record framework provides two common MOCS,rootSavingContextIt is used for docking […]

  • Coredata collation (4) — data migration and other issues


    Coredata collation (4) — data migration and other issues Catalog Lightweight data migration Subsequent problems Lightweight data migration In the process of iteration of APP version, it is inevitable to change the. Xcdatamodel file, such as adding or deleting an entity, adding or deleting the attributes of an original entity, etc. If you do not […]

  • Introduction to SQLite


    sqlite Official document: https://www.sqlitetutorial.ne…Rookie tutorial: https://www.runoob.com/sqlite… To import SQL files from the command line Connect (open database) For example, there is test.db in the current folder sqlite>.open test.db Check which databases are connected sqlite>.databases Import SQL file For example, there is test.sql in the current folder sqlite>.read test.sql View all table names sqlite>.tables Checklist structure […]

  • Python Ethereum blockchain interaction stores data into database


    Introductory workshops on blockchain usually start with stories like easy to understand point-to-point networks and bank ledgers, and then jump directly to writing smart contracts, which seems very abrupt. So imagine yourself walking into the jungle, and the Ethereum blockchain is a strange creature you are about to study. Today we will look at the […]

  • A brief introduction to SQLite and usage scenarios


    What is SQLite? SQLite is a lightweight embedded database. Its database is a file. Small embedded systems, similar to mysql, are smaller and have relatively few functions. They occupy very low resources and may require only a few hundred kilograms of memory. It is a truly open source, unlimited database, cross-platform, supporting Linux, Mac, Android, […]

  • SQLite transaction model, performance optimization tips, common misunderstandings


    0, foreword. This paper mainly introduces the transaction model of SQLite and some performance optimization tips based on the transaction model, including transaction encapsulation, WAL + read-write separation, sub-database and sub-table, page size optimization, etc. Based on the current situation of hand-cleaning sqlite, this paper summarizes some common problems and misunderstandings, mainly focusing on the […]

  • Compatibility of Logic Operators of SQL Statements “AND”, “&&”


    Recently, I plan to transfer my blog to the Typecho platform, and choose a theme that I prefer personally, that is, Akina for Typecho theme template. First, I would like to thank the subject’s open source sharing, but at the beginning of the application, there appeared the problem of “500 Database Query Error”.Add the following […]

  • Detailed Explanation of SQLite Delete and Example Code


    Detailed Explanation of SQLite Delete The DETE query of SQLite is used to delete records already in the table. A DELETE query with a WHERE clause can be used to delete selected rows, otherwise all records will be deleted. grammar The basic grammar of DETE queries with WHERE clauses is as follows: DELETE FROM table_name […]

  • C-SQLite C Interface


    C Interface of SQLite A Brief Introduction to C Interface of SQLite sqlite3_open int sqlite3_open ( const char *filename, /* Database filename (UTF-8) */ /* The database will adopt UTF-8 encoding mode and SQLite 3_open16 will adopt UTF-16 encoding mode.*/ SQLite3 ** ppDb /* OUT: SQLite DB handle */ * database connection object*/ ): Open […]

  • C Interface for C-SQLite Analysis


    C/C++ Interface for SQLite Analysis Newbie Course: http://www.runoob.com/sqlite/…SQLite official API document: https://sqlite.com/capi3ref.h… Preface   SQLite3It is a new version of SQLite. Although it is developed on the basis of the code of SQLite 2, it uses database formats and APIs that are incompatible with previous versions. SQLite3 was developed to meet the following requirements: support UTF-16 […]

  • Analysis of Sqlite-SQLite


    Analysis of SQLite SQLite is a very lightweight and self-contained DBMS. It is portable, easy to use, small, efficient and reliable. SQLite is embedded in applications that use it, sharing the same process space, rather than a single process. Externally, it is not like an RDBMS, but internally, it is a complete, self-contained database engine. […]