12.30sqlite判断表、字段是否存在

1.判断表名是否存在:

select * from sqlite_master

sqlite_master 的表结构如下:

type |name |tbl_name |rootpage |sql

示范查询结果;

=============

type>>table

name>>android_metadata

tbl_name>>android_metadata

rootpage>>3

sql>>CREATE TABLE android_metadata (locale TEXT)

=============

type>>table

name>>TalkVO

tbl_name>>TalkVO

rootpage>>4

sql>>CREATE TABLE TalkVO (content text,videoPath text,img text,name text,issend BLOB,isPlaying integer,uid integer,_id integer PRIMARY KEY)

2.判断字段是否存在

PRAGMA table_info([TalkVO])

必须 大写,结构如下：

cid | name | type | notnull | dflt_value | pk

示范查询结果;

PRAGMA table_info([TalkVO])

=============

cid>>0

name>>content

type>>text

notnull>>0

dflt_value>>null

pk>>0

=============

cid>>1

1name>>videoPath

type>>text

notnull>>0

dflt_value>>null

pk>>0

=============

cid>>2

name>>img

type>>text

notnull>>0

dflt_value>>null

pk>>0

=============

cid>>3

name>>name

type>>text

notnull>>0

dflt_value>>null

pk>>0

=============

cid>>4

name>>issend

type>>BLOB

notnull>>0

dflt_value>>null

pk>>0

=============

cid>>5

name>>isPlaying

type>>integer

notnull>>0

dflt_value>>null

pk>>0

=============

cid>>6

name>>uid

type>>integer

notnull>>0

dflt_value>>null

pk>>0

=============

cid>>7

name>>_id

type>>integer

notnull>>0

dflt_value>>null

pk>>1