Android开发相关：(06)快速了解SQLite

[sql] // Set the column headers to show in the tool
sqlite>. headers on

// select all rows from a table
select * from table1;

// count the number of rows in a table
select count(*) from table1;

// select a specific set of columns
select col1, col2 from table1;

// select distinct values in a column
select distinct col1 from table1;

// counting the distinct valus
select count(col1) from (select distinct col1 from table1);

// group by
select count(*), col1 from table1 group by col1;

// regular inner join
select * from table1 t1, table2 t2 where t1.col1 = t2.col1;

// left outer join
// give me everything in t1 even though there are no rows in t2
select * from table t1 left outer join table2 t2 on t1.col1 = t2.col1 where ....
// Set the column headers to show in the tool
sqlite>. headers on

// select all rows from a table
select * from table1;

// count the number of rows in a table
select count(*) from table1;

// select a specific set of columns
select col1, col2 from table1;

// select distinct values in a column
select distinct col1 from table1;

// counting the distinct valus
select count(col1) from (select distinct col1 from table1);

// group by
select count(*), col1 from table1 group by col1;

// regular inner join
select * from table1 t1, table2 t2 where t1.col1 = t2.col1;

// left outer join
// give me everything in t1 even though there are no rows in t2
select * from table t1 left outer join table2 t2 on t1.col1 = t2.col1 where ....