---the use of sqlite in pure Swift

Sqlite.swift is an operating framework that encapsulates SQLite3 using the pure Swift language.

Characteristics:

• Simple query and parameter binding interface

• Secure, automated type of data access

• Implicit commit and rollback interfaces

• Developer-friendly error handling and debugging

• Document Perfection

• Through extensive testing

Demo Code:

Import Foundation/** 1. Open Database 2. If there is no data table, you need to first create table 3. Data Manipulation*/classSQLite {var db:copaquepointer=Nil///Open Database///    ///:p aram:dbname Database name///    ///: Returns: Whether to open successfullyFunc OpenDatabase (dbname:string)Bool {//unsafepointer<int8> unsafepointer<cchar>//corresponding to char* in C language//filename must be the full path nameLet path =Dbname.documentpath () println (path)//Sqlite3_open If the database does not exist, a new database file is created//if the database file already exists, open it directly and return the handle without any effect on the data        ifSqlite3_open (path, &db) = =SQLITE_OK {println ("Open Database succeeded")                        //essentially, it only needs to be run once.            ifcreatetable () {println ("success in the creation of a table")                                //TODO: Test query dataLet sql ="SELECT ID, Departmentno, Name from T_department;"recordSet (SQL)}Else{println ("failed to create a table")            }        } Else{println ("failed to open database")        }                return false    }        ///Create a data table, create a data table that the system needs, once    PrivateFunc createtable ()Bool {//prepare SQL for all data tables//1> Each SQL is completed with one; //2> Write all the Genesis SQL together, adding a \ n for each line breakLet sql ="CREATE TABLE \ n"+"IF not EXISTS t_department (\ n"+"ID INTEGER PRIMARY KEY autoincrement not null,\n"+"Departmentno CHAR (Ten) not NULL DEFAULT ' ', \ n"+"Name CHAR (a) 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 is not NULL, \ n"+"' department_id ' INTEGER, \ n"+"CONSTRAINT ' fk_dep_id ' FOREIGN KEY (' department_id ') REFERENCES ' t_department ' (' ID ') \ n"+");"                returnexecsql (SQL)}///Execute SQL statement with no return value///    ///:p aram:sql SQL string///    ///: Returns: whether successfulFunc Execsql (sql:string)Bool {/** 1. Database pointer 2. SQL string in C language format 3. Callback, which executes a function callback after the completion of the SQL instruction, usually nil 4. Pointer to the first parameter of the callback 5. Error messages, which are also usually passed to nil*/        returnSqlite3_exec (DB, sql.cstringusingencoding (nsutf8stringencoding)!, nil, nil, nil) = =SQLITE_OK}///Execute SQL Returns a result set (object array)///    ///:p aram:sql SQL stringfunc RecordSet (sql:string) {//1. Prepare the statementvar stmt:copaquepointer =Nil/** 1. Database handle 2. The C language of SQL string 3. The string length of the C language of SQL strlen,-1 automatically calculates 4. STMT's Pointer 5. Usually pass in nil*/        ifSQLITE3_PREPARE_V2 (DB, Sql.cstringusingencoding (nsutf8stringencoding)!,-1, &stmt, nil) = =SQLITE_OK {//single-Step Get SQL Execution results-Sqlite3_setup corresponds to a record             whileSqlite3_step (stmt) = =Sqlite_row {//get the data for each recordrecorddata (stmt)}} }        ///get a record of each piece of data///    ///:p aram:stmt prepared_statement Objectsfunc RecordData (stmt:copaquepointer) {//get to recordvar count =Sqlite3_column_count (stmt) println ("get to record, total number of columns \ (count)")        //traverse data for each column         forIinch 0.. <count {Let type=Sqlite3_column_type (stmt, i)//extracts the value of the corresponding column based on the type of the field            Switchtype { CaseSqlite_integer:println ("integer \ (sqlite3_column_int64 (stmt, i))")             CaseSqlite_float:println ("small tree \ (sqlite3_column_double (stmt, i))")             CaseSqlite_null:println ("empty \ (NSNull ())")             CaseSqlite_text:let chars= unsafepointer<cchar>(Sqlite3_column_text (stmt, i)) let str= String (Cstring:chars, encoding:nsutf8stringencoding)!println ("string \ (str)")             CaseLet type:println ("Unsupported type \ (type)")            }        }    }}

---the use of sqlite in pure Swift