zlikavac32/sql-query-parser

Small SELECT statement SQL parser for query builders

Tiny SQL Parser

Small ASCII only SQL parser for the SELECT statements intended to be used in query builders. The statement is decomposed into sections and placeholders are collected for each section. Only unnamed placeholders are supported which means that for every placeholder only it's offset within the section is recorded.

Currently this parser targets MySQL SQL grammar until version 8.0.

This library should parse any valid SELECT statement but it will also parse some invalid statements as valid. This is by design, since intention is to use this to parse already valid statements and this way grammar is simplified.

For more info about the library check include/tsqlp.h.

With the library comes standalone binary to decompose SELECT statements into sections called tsqlp.

For example, for the SQL

SELECT id, 2, ? + ? FROM t WHERE a = ?

tsqlp produces output

columns 2 7 11 12 id, 2, ? + ?
tables 0 1 t
where 1 4 5 a = ?

Statement contains three sections, columns, tables and where. Section column has 2 parameters at offsets 7 and 11 and is 12 bytes long. Then comes 12 bytes of the section content. Section tables contains 0 parameters and is 1 byte long. Content of the tables section is t. Finally, where section has 1 parameter at offset 4 and the content of that section is a = ? which is 5 bytes long.

Placeholders as table names

This parser supports placeholders as table name. That is something invalid in regular SQL but it's useful in query building.

For example, parser can parse SELECT * FROM ? and expose ? as a placeholder which can later have inline subquery or something else.

Installation

Clone this repository and within do the following.

cd build
cmake .. -DCMAKE_BUILD_TYPE=Release 
make
sudo make install

If you get tsqlp: error while loading shared libraries: libtsqlp.so: cannot open shared object file: No such file or directory make sure /usr/local/lib is used by the ldconfig or change install path.