FMDB 相关

  1 #import "ViewController.h"
  2
  3 #import "FMDBMigrationManager.h"
  4 #import "FMDB.h"
  5
  6 #define PATH_OF_DOCUMENT    [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]
  7 #define CREATE_TEACHER_TAB @"CREATE TABLE IF NOT EXISTS %@(content text,time text)"
  8 //插入基础元素
  9 #define INSERT_SQL @"insert into %@(content, time) values(?,?)"
 10
 11 @interface ViewController () {
 12
 13     FMDatabaseQueue *dbQueue;
 14 }
 15
 16 @end
 17
 18 @implementation ViewController
 19
 20 - (void)viewDidLoad {
 21     [super viewDidLoad];
 22     // Do any additional setup after loading the view, typically from a nib.
 23
 24     NSString * doc = PATH_OF_DOCUMENT;
 25     NSString * path = [doc stringByAppendingPathComponent:@"teacherCache.sqlite"];
 26
 27     if (!dbQueue) {
 28
 29         dbQueue = [FMDatabaseQueue databaseQueueWithPath:path];
 30     }
 31
 32     [self createTable:@"user"];
 33 }
 34
 35 - (NSString *)databaseFilePath {
 36
 37     NSString * doc = PATH_OF_DOCUMENT;
 38     NSString * path = [doc stringByAppendingPathComponent:@"teacherCache.sqlite"];
 39     return path;
 40 }
 41
 42 - (void)didReceiveMemoryWarning {
 43     [super didReceiveMemoryWarning];
 44     // Dispose of any resources that can be recreated.
 45 }
 46
 47 - (BOOL)isTableExist:(NSString *)tableName {
 48
 49     FMDatabase *db = [FMDatabase databaseWithPath:[self databaseFilePath]];
 50     if ([db open]) {
 51
 52         FMResultSet *rs = [db executeQuery:@"select count(*) as ‘count‘ from sqlite_master where type =‘table‘ and name = ?", tableName];
 53         while ([rs next]) {
 54
 55             // just print out what we‘ve got in a number of formats.
 56             NSInteger count = [rs intForColumn:@"count"];
 57
 58             [db close];
 59
 60             if (count <= 0) {
 61
 62                 return NO;
 63             }else {
 64
 65                 return YES;
 66             }
 67         }
 68         [db close];
 69     }else {
 70
 71         NSLog(@"error when open db");
 72     }
 73
 74     return NO;
 75 }
 76
 77 - (void)createTable:(NSString*)table {
 78
 79     if ([self isTableExist:table]) {
 80
 81         NSLog(@"table exist already");
 82
 83         NSLog(@"alter now");
 84         FMDatabase *db = [FMDatabase databaseWithPath:[self databaseFilePath]];
 85         if ([db open]) {
 86             if (![db columnExists:@"noe" inTableWithName:table]) {
 87
 88                 [self alterTable:table];
 89             }
 90
 91             [db close];
 92         }
 93
 94         return;
 95     }
 96     FMDatabase *db = [FMDatabase databaseWithPath:[self databaseFilePath]];
 97     if ([db open]) {
 98
 99         NSString *sSQL = [NSString stringWithFormat:CREATE_TEACHER_TAB, table];
100         BOOL res = [db executeUpdate:sSQL];
101         if (!res) {
102
103             NSLog(@"error when creating db table");
104         }else {
105
106             NSLog(@"succ to creating db table");
107
108             [self insertContentTable:table Content:@"ssfdsf" Time:@"2015-04-05"];
109         }
110         [db close];
111
112     }else {
113
114         NSLog(@"error when open db");
115     }
116 }
117
118 - (void)insertContentTable:(NSString*)table Content:(NSString*)content Time:(NSString *)time
119 {
120     [dbQueue inDatabase:^(FMDatabase *db)
121      {
122          NSString *sql = [NSString stringWithFormat:INSERT_SQL,table];
123
124          BOOL res = [db executeUpdate:sql,content,time];
125          if (!res)
126          {
127              NSLog(@"error when insertContentTable");
128          }
129          else
130          {
131              NSLog(@"succ to insertContentTable");
132          }
133      }];
134 }
135
136 - (void)alterTable:(NSString*)table {
137
138     [dbQueue inDatabase:^(FMDatabase *db) {
139
140          NSString *sql = [NSString stringWithFormat:@"ALTER TABLE %@ ADD %@ text",table, @"noe"];
141
142          BOOL res = [db executeUpdate:sql];
143          if (!res)
144          {
145              NSLog(@"error when alterTable");
146          }
147          else
148          {
149              NSLog(@"succ to alterTable");
150          }
151      }];
152 }