--- Using SQLite in Swift, --- swiftsqlite

--- Using SQLite in Swift, --- swiftsqlite

SQLite. swift is an operating framework that uses the pure Swift language to encapsulate SQLite3.

Features:

• Simple query and parameter binding Interfaces

• Secure and Automatic Data Access

• Implicit commit and rollback APIs

• Developer-friendly error handling and debugging

• Comprehensive documentation

• Passed extensive tests

DEMO code:

Import Foundation/** 1. open Database 2. if no data table exists, create table 3 first. data operation */class SQLite {var db: COpaquePointer = nil // open the database //: param: dbname database name ////: returns: func openDatabase (dbname: String) Enabled) -> Bool {// UnsafePointer <Int8> UnsafePointer <CChar> // the char in the C language * // the filename must be the complete path name. let path = dbname.doc umentPath () println (path) // sqlite3_open if the database does not exist, a new database file will be created. // if the database file already exists, open it directly and return a handle, It does not affect the data. if sqlite3_open (path, & db) = SQLITE_ OK {println ("") // In essence, you only need to run it once. if createTable () {println ("") // TODO: test the data query. let SQL = "SELECT id, DepartmentNo, Name FROM T_Department;" recordSet (SQL )} else {println ("failed to create a table")} else {println ("failed to open the Database")} return false} // create a data table and set the data table required by the system, one-time creation of private func createTable ()-> Bool {// prepare SQL statements for all data tables // 1> after each SQL statement is completed, a private func createTable () Write SQL statements in an invasive table together, add a \ n let SQL = "CREATE TABLE \ n" + "IF NOT EXISTS T_Department (\ n" + "id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, \ n "+" DepartmentNo CHAR (10) not null default '', \ n" + "Name CHAR (50) not null default'' \ n "+ "); \ n "+" create table if not exists T_Employee (\ n "+" 'id' integer not null primary key autoincrement, \ n "+" 'name' text not null, \ n "+" 'age' integer not null, \ N "+" 'department _ id' INTEGER, \ n "+" CONSTRAINT 'fk _ DEP_ID 'foreign key ('department _ id ') REFERENCES't _ Department '('id') \ n "+"); "return execSQL (SQL )} /// execute the SQL statement that does not return a value /////: param: SQL SQL String /////: returns: whether func execSQL is successful (SQL: String) -> Bool {/** 1. database pointer 2. SQL string C Format 3. callback: The function callback after the SQL command is executed, usually nil 4. pointer of the first parameter of the callback 5. error message, which is usually passed into nil */return sqlite3_exec (db, SQL. cStr IngUsingEncoding (NSUTF8StringEncoding )!, Nil, nil, nil) = SQLITE_ OK} // run the SQL statement to return a result set (Object array) //: param: SQL SQL string func recordSet (SQL: string) {// 1. prepare the statement var stmt: COpaquePointer = nil/** 1. database handle 2. SQL C string 3. the string length of the SQL C language is strlen,-1 is automatically calculated 4. stmt pointer 5. generally, nil */if sqlite3_prepare_v2 (db, SQL. cStringUsingEncoding (NSUTF8StringEncoding )!, -1, & stmt, nil) = SQLITE_ OK {// obtain the SQL Execution result in one step-> sqlite3_setup corresponds to a record while sqlite3_step (stmt) = SQLITE_ROW {// obtain the data recordData (stmt) of each record }}/// obtain the record of each record //: param: stmt prepared_statement object func recordData (stmt: COpaquePointer) {// retrieve record var count = sqlite3_column_count (stmt) println ("retrieve record, total number of columns \ (count )") // traverse the data in each column for I in 0 .. <count {let type = sqlite3_column_type (stmt, I) // Extract the switch type {case SQLITE_INTEGER: println ("integer \ (sqlite3_column_int64 (stmt, I)") case SQLITE_FLOAT Based on the field type: println (" \ (sqlite3_column_double (stmt, I)") case SQLITE_NULL: println ("null \ (NSNull ()") case SQLITE_TEXT: let chars = UnsafePointer <CChar> (sqlite3_column_text (stmt, I) let str = String (CString: chars, encoding: NSUTF8StringEncoding )! Println ("string \ (str)") case let type: println ("unsupported type \ (type )")}}}}