About creating SQL for search functions.

For each search item, use the OR operator to connect the conditions under which the input is empty and true in a partial match search.
If the input is empty, the search criteria are ignored, and only if the input is not empty, the partial match search is reflected.

For example, for the schema below,

CREATE TABLE Tbl
(col1VARCHAR(10) NOT NULL
, col2VARCHAR(10) NOT NULL
);

Queries for col1,col2 can be written using the parameters :1 through :4 as follows:
(Search input with parameter :1,:2 as col1.Search input with parameter :3,:4 is col2)

SELECT col1,col2
FROM Tbl
WHERE (NULLIF(:1,') IS NULL OR col1 LIKE('%'||:2|'%')
  AND (NULLIF(:3,') IS NULL OR col2 LIKE('%'|:4|'%')
ORDER BY COL1, COL2
;

Each RDBMS has a different description of the parameters, so please adjust it if it does not work as it is.
Example: MySQL Results

As a precondition, the search value for the criteria is using PreparedStatement, and the flow of SQL statements specified there will be as follows.

Check the total number of conditions
Zero decision specification → No WHERE clause
One decision specification → Create a WHERE clause and enter conditions
There are two or more decisions → First, create a WHERE clause and enter conditions, and from the second
Add an AND condition.

Depending on how the input is received, the content of the code may change to for statement or access to array, but I think it would be good to consider the total number of conditions for assembly.