IOS sqlite 基础，iossqlite基础
1，导入libsqlite3.0.dylib库
文件中：#import"sqlite3.h"
2，创建数据库
#define kDocDir [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]
#define dbPath [kDocDir stringByAppendingPathComponent:@"test.db"]
sqlite3 *db;
if (sqlite3_open([dbPath UTF8String], &db) !=SQLITE_OK) {
sqlite3_close(db);
NSAssert(0,@"数据库打开失败。");
return;
}
3，创建表table1, 三个不同类型的字段id是整形，name是字符串，image是二进制
char *sqlStr ="CREATE TABLE table1 (id integer, name text, image blob)";
sqlite3_stmt *statement;
if(sqlite3_prepare_v2(db, sqlStr, -1, &statement,nil) !=SQLITE_OK) {
NSLog(@"Error: failed to prepare statement:create table1");
return;
}
int success = sqlite3_step(statement);
sqlite3_finalize(statement);
if ( success != SQLITE_DONE) {
NSLog(@"Error: failed to dehydrate:CREATE TABLEtable1");
return;
}
4，插入数据，注意问号的个数要和参数匹配
int idvalue;
NSString *namevalue";
NSData *image;
sqlStr = "INSERT INTO table1 VALUES(?,?,?)";
int success = sqlite3_prepare_v2(db, sqlStr, -1, &statement,NULL);
if (success != SQLITE_OK) {
NSLog(@"Error: failed to insert into table1");
}
sqlite3_bind_int(statement, 1, [idvalue integerValue]);//第二个参数从1开始，与后面查询数据的时候有区别
sqlite3_bind_text(statement, 2, [namevalue UTF8String], -1,SQLITE_TRANSIENT);
sqlite3_bind_blob(statement, 3, [image bytes], (int)[image length],SQLITE_TRANSIENT);
success = sqlite3_step(statement);
sqlite3_finalize(statement);
if (success == SQLITE_ERROR) {
NSLog(@"Error: failed to insert into the database with message.");
return;
}
5, 查询数据
sqlStr = "SELECT * FROM table1";
if (sqlite3_prepare_v2(db, sqlStr, -1, &statement,NULL) !=SQLITE_OK) {
NSLog(@"Error: failed to prepare statement with message:gettable1.");
return;
}
//查询结果集中一条一条的遍历所有的记录，这里的数字对应的是列值。
while (sqlite3_step(statement) ==SQLITE_ROW) {
int tempint=sqlite3_column_int(statement, 0);//这里要从0开始，注意与插入的时候序号的区别
char *temp=(char *)sqlite3_column_text(statement, 1);
NSString *tempstr=temp?[NSString stringWithUTF8String:temp]:@"";
int length=sqlite3_column_bytes(statement,2);//获取到二进制的数据的长度
Byte* bytes=(Byte*)sqlite3_column_blob(statement,2);
NSData *data=[NSData dataWithBytes:byteslength:length];
}
6，关闭数据库
sqlite3_close(db);