The Non-Callback API

The non-callback API provides an alternative way to retrieve data from a SQLite database by compiling an SQL statement into a virtual machine of type sqlite_vm:

 typedef struct sqlite_vm sqlite_vm; 

Creating a Virtual Machine

You can create a SQLite virtual machine as follows:

 int sqlite_compile(   sqlite *db,              /* The open database */   const char *zSql,        /* SQL statement to be compiled */   const char **pzTail,     /* OUT: uncompiled tail of zSql */   sqlite_vm **ppVm,        /* OUT: the virtual machine to execute zSql */   char **pzErrmsg          /* OUT: Error message. */ ); 

The return code from sqlite_compile() is SQLITE_OK if the operation is successful; otherwise, one of the error codes listed in the preceding example is returned.

Step-by-Step Execution of an SQL Statement

Each invocation of sqlite_step() for a virtual machine, except the last one, returns a single row of the result:

 int sqlite_step(   sqlite_vm *pVm,          /* The virtual machine to execute */   int *pN,                 /* OUT: Number of columns in result */   const char ***pazValue,  /* OUT: Column data */   const char ***pazColName /* OUT: Column names and datatypes */ ); int sqlite_finalize(   sqlite_vm *pVm,          /* The virtual machine to be finalized */   char **pzErrMsg          /* OUT: Error message */ ); 

Return Codes

The return code from sqlite_step() can be SQLITE_BUSY, SQLITE_ERROR, SQLITE_MISUSE, or either of the following.

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

Indicates that another row of result data is available.

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

Indicates that the SQL statement has been completely executed and sqlite_finalize() should now be called.

The return code from sqlite_finalize() indicates the overall success of the SQL command and will be the same as if the query had been executed using sqlite_exec().