sqlite3 xx.db
.dbinfo
有时该命令报错
使用这个语句 pragma user_version；
下面我们看看sqlite到底有些有用的pragma命令，用到时再去研究：
auto_vacuum
automatic_index
cache_size
case_sensitive_like
checkpoint_fullfsync
collation_list
compile_options
count_changes¹
database_list
default_cache_size¹
empty_result_callbacks¹
encoding
foreign_key_list
foreign_keys
freelist_count
full_column_names¹
fullfsync
ignore_check_constraints
incremental_vacuum
index_info
index_list
integrity_check
journal_mode
journal_size_limit
legacy_file_format
locking_mode
max_page_count
page_count
page_size
parser_trace²
quick_check
read_uncommitted
recursive_triggers
reverse_unordered_selects
schema_version
secure_delete
short_column_names¹
synchronous
table_info
temp_store
temp_store_directory¹
user_version
vdbe_listing²
vdbe_trace²
wal_autocheckpoint
wal_checkpoint
writable_schema
这里边有几个标了右上标为1的，似乎已经被obsoleted掉了。标为2的，只被用于debug,仅当sqlite在预编译宏SQLITE_DEBUG下build出来，才有用。
