Definition of SQLite Extension
The extension is used for manipulating the data that means we can export the different tables from the SQLite database to your selected environment and perform the different commands. SQLite extension is capable of handling more than one database and interacting with all at the same time as per the user requirement. Basically, SQLite database does not require any name conventions but at the same time when we think about the other programming language, it will be problematic to the system as well as the end-user. Another use of SQLite extension is that we can easily sort the database file on their file type.
Syntax:
There is multiple syntaxes available in SQLite to implement the SQLite extension, but we only discuss creating table syntax that is related to JSON extension as follows.
create table [If table name not exists] specified table name (colm name 1 data type, colm name 2 data type, colm N data type);
Explanation
In the above syntax, we use the create table statement to create a new table; here the specified table name means the name of the table that we need to create. In SQLite table names we cannot start with sqlite because of internal use of SQLite.
How extension works in SQLite?
Basically, SQLite extension included data manipulation, data definition language command, and that command we can use as per the user the requirement, so let’s see how SQLite extension works as follows.
After Execution
After execution means it handles the event after the execution of the SQL statement and it displays the weather SQL statement successfully executed.
After Query
After query execution is displayed the selected data from and a number of rows from the database.
Error Occurred
This parameter is used to show the error from the SQL statement that is the error message.
Query
Execute pre-ordered QUERY statement with determined boundaries.
Boundaries:
1) String table: specified name of the table that we want.
2) YailList columns: List of different columns that we need to return.
3) String determination: Filter announcing which columns to return, designed as a SQL WHERE condition, passing a vacant string will return all lines.
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4) YailList selectionArgs: List of the different arguments that we need to replace.
5) String groupBy: the group by clause is used to sort the data or rows as per the user requirement by providing the different conditions; if a column is empty then group by clause is not working.
6) String having: A channel announces which row gatherings to incorporate if push gathering is being utilized, passing an unfilled string will cause all column gatherings to be incorporated.
7) String orderBy: How to arrange the columns, designed as a SQL ORDER BY statement (barring the ORDER BY itself), passing an unfilled string will utilize the default sort request (unordered).
8) String limit: Limits the number of columns returned by the inquiry, organized as a LIMIT statement, passing an unfilled string means no Restriction provision. Return: The outcome question is accessible in the AfterQuery occasion overseer.
Insert
It is used to execute the insert statement with certain parameters.
Replace
Execute pre-aggregated REPLACE OR INSERT INTO proclamation with indicated boundaries.
Boundaries:
1) String table: specified name of the table that we want.
2) YailList Column: It is a list of columns that contains the information about the database.
3) YailList esteems List with the information to be supplanted in the data set. Return the column ID of the recently supplanted row, or – 1 if an error occurred.
Update
It executed an update statement with the specified parameter and it also has some boundaries the same like replace.
Delete
Execute pre-ordered DELETE proclamation with determined boundaries.
Boundaries:
1) String table: specified name of the table that we want.
2) String whereClause: the where clause is an option part of delete statement, if we don’t use the where clause then it deletes the entire table from the database, and if we use where clause then it removes the specific record from the table.
3) List whereArgs: List with contentions for the WHERE statement. These contentions will be supplanted by ‘?’ in the whereClause. Returns the number of columns influenced if a whereClause is passed in, 0 in any case.
SingleSQL
Single SQL parameter is used to execute the only single query statement and it displays whether a statement is executed successfully or not.
MultipleSQL
Multi SQL parameter is used to execute the multiple query statement and it displays whether the statement is executed successfully or not.
RawQuery
After execution of the raw query, it provides the selected data that the user wants.
GetPath
It is used to provide the path of all databases.
ClearDatabase
It is used to clear the database version.
ReturnHeader
It is used to return the header row from the specified table.
Examples
Now let’s see a different example of SQLite extension as follows.
create table jsn_tre(number any, value any, dept text, item any, p_id integer, path text, json JSON HIDDEN, root text hidden);
Explanation
In the above example, we use a create table statement to create a new table name as jsn_tre with different attributes and different data types. In this example, the number is the integer array index for the JSON array. The item column is SQL value and it corresponds to the elements of JSON. The item value is null for JSON array and object. dept is a SQL text and it accepts text values such as null, true, integer, array and object, etc. End output of the above statement we illustrate by using the following screenshot.
.table
Suppose we have a table name as emp with attributes such as emp_name and emp_phone and it stores more than one value in emp_phone column including the zero. Suppose we need to find out whose emp has phone 104 at that time we can use the following statement as follows.
select distinct emp.emp_name from emp, json_each(user.phone) where json_each.value like ‘104%’;
Explanation
See here we use the JSON array concept that means emp_phone column stores the multiple values and json_each() only calls when those users have more than one value. End output of the above statement we illustrate by using the following screenshot.
Conclusion
We hope from this article you have understood about SQLite Extension. From the above article, we have learned the basic syntax of Extension statements and we also see different examples of Extension. We also learned the rules of Extension. From this article, we learned how and when we use SQLite Extension.
Recommended Articles
This is a guide to SQLite Extension. Here we discuss Introduction, syntax, and How extension works in SQLite? with examples. You may also have a look at the following articles to learn more –
