SQLite BLOB Tools - Import, Export, View and Edit

• Import file data to SQLite BLOB
• Export SQLite BLOB data to files
• View and edit BLOB data stored in SQLite
• View and edit image stored in SQLite BLOB field
• View PDF stored in SQLite BLOB field
• Batch export SQLite query results BLOB data to files
• Batch update SQLite table BLOB data from files
• Batch insert SQLite table BLOB data from files

SQLite BLOB - type family and size limits

Type in SQLite	Maximum size
BLOB	a storage class, not a hard type - the real limit comes from SQLITE_MAX_LENGTH
SQLITE_MAX_LENGTH	compile-time default 1,000,000,000 (about 1 GB)

BLOB versus CLOB in SQLite

SQLite is dynamically typed: declaring a column BLOB or TEXT only sets its type affinity, and what is actually stored is decided by the value written. Declaring a column CLOB does not give you CLOB semantics.

What limits you first

SQLITE_MAX_LENGTH, a compile-time constant defaulting to one billion bytes. That figure is more accurate than "1 GB", and the only way to change it is to rebuild SQLite - there is no runtime setting.

BLOB from the command line

• Export: .dump (text SQL, BLOBs become X'...' literals) or VACUUM INTO 'new.db'
• Import: .import, or the readfile() function

Things that bite with BLOB in SQLite

• .dump emits BLOBs as X'...' hex literals, so a database with large objects produces a dump more than twice the size - use VACUUM INTO or sqlite3_backup to move a whole file
• SQLITE_MAX_LENGTH is fixed at build time and cannot be raised at runtime
• Declaring VARCHAR(n) does not enforce the length - SQLite happily stores longer values