[iPhone-Sqlite3]sqlite3_prepare_v2() 不返回 SQLITE_OK,调试

时间:2022-06-01 18:37:51

这是关于这个整形的定义。

#define SQLITE_OK           0   /* Successful result */

/* beginning-of-error-codes */

#define SQLITE_ERROR        1   /* SQL error or missing database */

#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */

#define SQLITE_PERM         3   /* Access permission denied */

#define SQLITE_ABORT        4   /* Callback routine requested an abort */

#define SQLITE_BUSY         5   /* The database file is locked */

#define SQLITE_LOCKED       6   /* A table in the database is locked */

#define SQLITE_NOMEM        7   /* A malloc() failed */

#define SQLITE_READONLY     8   /* Attempt to write a readonly database */

#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/

#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */

#define SQLITE_CORRUPT     11   /* The database disk image is malformed */

#define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */

#define SQLITE_FULL        13   /* Insertion failed because database is full */

#define SQLITE_CANTOPEN    14   /* Unable to open the database file */

#define SQLITE_PROTOCOL    15   /* NOT USED. Database lock protocol error */

#define SQLITE_EMPTY       16   /* Database is empty */

#define SQLITE_SCHEMA      17   /* The database schema changed */

#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */

#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */

#define SQLITE_MISMATCH    20   /* Data type mismatch */

#define SQLITE_MISUSE      21   /* Library used incorrectly */

#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */

#define SQLITE_AUTH        23   /* Authorization denied */

#define SQLITE_FORMAT      24   /* Auxiliary database format error */

#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */

#define SQLITE_NOTADB      26   /* File opened that is not a database file */

#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */

#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */ 

 

当调用 sqlite3_prepare_v2() 函数的时候,是一个将SQL语句编译为sqlite内部一个结构体(sqlite3_stmt).

该结构体中包含了将要执行的的SQL语句的信息.

通常情况下,应该是返回0。还有一些时候是返回其他数值。

我以1为例,简单介绍一下错误解决的思路和方法:

 #define SQLITE_ERROR        1   /* SQL error or missing database */

 

我们尝试用以下代码来进行测试:

// Get the path to the documents directory and append the databaseName

NSString *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDir = [documentPaths objectAtIndex:0];

databasePath = [documentsDir stringByAppendingPathComponent:databaseName];

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *path = [documentsDirectory stringByAppendingPathComponent:databaseName];

    NSFileManager *fileManager = [NSFileManager defaultManager];

      上面的这个path,我们可以看到,我们需要连接的数据库的那个路径。有时候,如果你的工程创建好了以后,在运行时会把database复制到这个路径下面。如果中途数据库发生了变化,随之有可能没有拷贝过去,那么这个路径下的数据库文件会和你工程里面的不一致。也许这个path下面的是一个大小为0字节的空数据库。所以通常即便是发现了数据库的存在,但是也不能保证你数据库的结构体是正确的。


    BOOL find = [fileManager fileExistsAtPath:path];

   

    if (find) {

        NSLog(@"Database file have already existed.");

        if(sqlite3_open([path UTF8String], &database_) != SQLITE_OK) {

            sqlite3_close(database_);

            NSLog(@"Error: open database file.");

            return NO;

        }

        return YES;

    }

else {

        sqlite3_close(database_);

        NSLog(@"Error: open database file.");

        return NO;

    } 

上面是打开的代码。下一篇,我将要分享一下如何购建一个SqliteHelper类及其方法。

 

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