#Android non sqlite database tutorial how to
#Android non sqlite database tutorial update
#Android non sqlite database tutorial code

#Android non sqlite database tutorial code

For example, to get tracks of the album 1 that have the length greater than 200,000 milliseconds, you use the following statement: SELECT name,Īlbumid = 1 AND milliseconds > 250000 Code language: SQL (Structured Query Language) ( sql ) You use the logical operator to combine expressions. In case you compare values in different data types e.g., a string with a number, SQLite has to perform implicit data type conversions, but in general, you should avoid doing this. You should compare numbers with numbers, string with strings, etc. When you compare two values, you must ensure that they are the same data type. Only the rows that satisfy the condition are returned. SQLite compares the values stored in the AlbumId column with a literal value 1 to test if they are equal. For example, the following query uses the WHERE clause the equality operator to find all the tracks in the album id 1: SELECT name,Īlbumid = 1 Code language: SQL (Structured Query Language) ( sql ) The equality operator ( =) is the most commonly used operator.

#Android non sqlite database tutorial how to

We will use the tracks table in the sample database to illustrate how to use the WHERE clause. Reverses the value of other operators such as NOT EXISTS, NOT IN, NOT BETWEEN, etc. Returns 1 if a value is in a list of values. Returns 1 if a subquery contains any rows. Returns 1 if any one of a set of comparisons is 1. Returns 1 if both expressions are 1, and 0 if one of the expressions is 0. The following table illustrates the SQLite logical operators: Operator Notice that SQLite does not provide Boolean data type therefore 1 means TRUE, and 0 means FALSE. A logical operator returns 1, 0, or a NULL value.

Logical operators allow you to test the truth of some expressions. The following table illustrates the comparison operators that you can use to construct expressions: Operator SQLite comparison operatorsĪ comparison operator tests if two expressions are the same.

#Android non sqlite database tutorial update

WHERE column_4 BETWEEN 10 AND 20 Code language: SQL (Structured Query Language) ( sql )īesides the SELECT statement, you can use the WHERE clause in the UPDATE and DELETE statements. The search condition in the WHERE has the following form: left_expression COMPARISON_OPERATOR right_expression Code language: SQL (Structured Query Language) ( sql )įor example, you can form a search condition as follows: WHERE column_1 = 100 Third, make the final result set based on the rows in the previous step with columns in the SELECT clause.Second, evaluate the conditions in the WHERE clause to get the rows that met these conditions.First, check the table in the FROM clause.When evaluating a SELECT statement with a WHERE clause, SQLite uses the following steps: In this example, you add a WHERE clause to the SELECT statement to filter rows returned by the query. Search_condition Code language: SQL (Structured Query Language) ( sql ) It appears after the FROM clause as the following statement: SELECT The WHERE clause is an optional clause of the SELECT statement. Summary: in this tutorial, you will learn how to use SQLite WHERE clause to specify the search condition for rows returned by the query.