.Dd December 19, 2018
.Dt SQLITE3_BLOB_READ 3
.Os
.Sh NAME
.Nm sqlite3_blob_read
.Nd Read Data From A BLOB Incrementally
.Sh SYNOPSIS
.Ft int 
.Fo sqlite3_blob_read
.Fa "sqlite3_blob *"
.Fa "void *Z"
.Fa "int N"
.Fa "int iOffset"
.Fc
.Sh DESCRIPTION
This function is used to read data from an open BLOB handle
into a caller-supplied buffer.
N bytes of data are copied into buffer Z from the open BLOB, starting
at offset iOffset.
.Pp
If offset iOffset is less than N bytes from the end of the BLOB, SQLITE_ERROR
is returned and no data is read.
If N or iOffset is less than zero, SQLITE_ERROR is returned
and no data is read.
The size of the blob (and hence the maximum value of N+iOffset) can
be determined using the sqlite3_blob_bytes() interface.
.Pp
An attempt to read from an expired BLOB handle fails with
an error code of SQLITE_ABORT.
.Pp
On success, sqlite3_blob_read() returns SQLITE_OK.
Otherwise, an error code or an extended error code
is returned.
.Pp
This routine only works on a BLOB handle which has been
created by a prior successful call to sqlite3_blob_open()
and which has not been closed by sqlite3_blob_close().
Passing any other pointer in to this routine results in undefined and
probably undesirable behavior.
.Pp
.Sh SEE ALSO
.Xr sqlite3_blob 3 ,
.Xr sqlite3_blob_bytes 3 ,
.Xr sqlite3_blob_close 3 ,
.Xr sqlite3_blob_open 3 ,
.Xr sqlite3_blob_write 3 ,
.Xr SQLITE_OK 3