How to use wildcards in the SELECT clause in SQLite

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The SELECT clause in SQLite uses wildcards

Two wildcards, * and table_name.*, are supported in the SELECT clause. Where the * wildcard outputs all user-defined columns of each source table in the FROM clause. For example, the following SQL statement outputs all user-defined columns for Students.

SELECT * FROM Students

Run the program, and the execution effect is shown in figure 3.5.

Figure 3.5 * wildcard

Table_name.* can be used to specify the name of the table where the output column is located, where the output columns are user-defined. Although both * and table_name.* wildcards can output multiple columns, neither of them will output automatically generated ROWID columns. If you want to output both ROWID and user-defined columns, you need to specify the ROWID column manually. The syntax is as follows:

SELECT ROWID, * FROM table_name

For example, the following SQL statement outputs all the columns in the Students table, including the automatically generated ROWID column.

SELECT ROWID,* FROM Students

Run the program, and the execution effect is shown in figure 3.6.

Figure 3.6 outputs all columns

Note: wildcards cannot use column aliases because they usually return multiple columns.

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