Skip to content

Adding MySQL Code Generator #27

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
WKaiZ wants to merge 1 commit into from
Closed

Adding MySQL Code Generator #27

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions src/main/java/org/qed/Generated/MySQL/FilterMerge.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
INSERT INTO query_rewrite.rewrite_rules
(pattern, replacement) VALUES(
'SELECT * FROM (SELECT * FROM Source WHERE ? = ?) AS t0 WHERE ? = ?',
'SELECT * FROM Source WHERE ? = ? AND ? = ?'
);
5 changes: 5 additions & 0 deletions src/main/java/org/qed/Generated/MySQL/ProjectMerge.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
INSERT INTO query_rewrite.rewrite_rules
(pattern, replacement) VALUES(
'SELECT ? FROM (SELECT ? FROM (SELECT * FROM Source) AS t0) AS t1',
'SELECT ?, ? FROM Source'
);
106 changes: 106 additions & 0 deletions src/main/java/org/qed/Generated/MySQLGenerator.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,106 @@
package org.qed.Generated;

import org.qed.RelRN;
import org.qed.RexRN;

import java.util.ArrayList;
import java.util.List;

public class MySQLGenerator {

private int subqueryCounter = 0;

private static class FlattenedSQLParts {
String fromClause = "";
List<String> projections = new ArrayList<>();
List<String> conditions = new ArrayList<>();
}

public String translate(String name, RelRN before, RelRN after) {
subqueryCounter = 0;

String beforeSQL = transformNested(before, true);

String afterSQL = transformFlatten(after);

return "INSERT INTO query_rewrite.rewrite_rules\n" +
"\t(pattern, replacement) VALUES(\n" +
"\t'" + beforeSQL + "',\n" +
"\t'" + afterSQL + "'\n" +
");";
}

public String transformNested(RelRN node, boolean isRoot) {
return switch (node) {
case RelRN.Scan scan -> "SELECT * FROM " + scan.name();
case RelRN.Project project -> {
String innerSQL = transformNested(project.source(), false);
String alias = "t" + (subqueryCounter++);
yield "SELECT ? FROM (" + innerSQL + ") AS " + alias;
}
case RelRN.Filter filter -> {
String innerSQL = transformNested(filter.source(), false);
String condSQL = "? = ?";
if (isRoot) {
yield innerSQL + " WHERE " + condSQL;
} else {
String alias = "t" + (subqueryCounter++);
yield "SELECT * FROM (" + innerSQL + " WHERE " + condSQL + ") AS " + alias;
}
}
default -> throw new UnsupportedOperationException("Unsupported RelRN: " + node);
};
}

public String transformFlatten(RelRN node) {
FlattenedSQLParts parts = new FlattenedSQLParts();
collectFlattenedParts(node, parts);

String selectClause = parts.projections.isEmpty()
? "SELECT *"
: "SELECT " + String.join(", ", parts.projections);

String whereClause = parts.conditions.isEmpty()
? ""
: " WHERE " + String.join(" AND ", parts.conditions);

return selectClause + " FROM " + parts.fromClause + whereClause;
}

private void collectFlattenedParts(RelRN node, FlattenedSQLParts parts) {
switch (node) {
case RelRN.Scan scan -> parts.fromClause = scan.name();
case RelRN.Project project -> {
collectFlattenedParts(project.source(), parts);
addPlaceholdersForRex(project.map(), parts.projections);
}
case RelRN.Filter filter -> {
collectFlattenedParts(filter.source(), parts);
collectPredConditions(filter.cond(), parts.conditions);
}
default -> throw new UnsupportedOperationException("Unsupported RelRN: " + node);
}
}

private void addPlaceholdersForRex(RexRN rex, List<String> projections) {
if (rex instanceof RexRN.Proj proj) {
projections.add("?");
for (RexRN source : proj.sources()) {
addPlaceholdersForRex(source, projections);
}
}
}

private void collectPredConditions(RexRN pred, List<String> conditions) {
switch (pred) {
case RexRN.Pred p -> conditions.add("? = ?");
case RexRN.And and -> {
for (RexRN child : and.sources()) {
collectPredConditions(child, conditions);
}
}
default -> throw new UnsupportedOperationException("Unsupported RexRN: " + pred);
}
}
}

33 changes: 33 additions & 0 deletions src/main/java/org/qed/Generated/MySQLTester.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,33 @@
package org.qed.Generated;

import kala.collection.Seq;
import kala.tuple.Tuple;
import kala.tuple.Tuple2;
import org.qed.*;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

public class MySQLTester {

public static String genPath = "src/main/java/org/qed/Generated/MySQL";

public static void main(String[] args) {
var rule = new org.qed.Generated.RRuleInstances.FilterMerge();
new MySQLTester().serialize(rule, genPath);
}

public void serialize(RRule rule, String path) {
var generator = new MySQLGenerator();
var codeGen = generator.translate(rule.name(), rule.before(), rule.after());
try {
Files.createDirectories(Path.of(path));
Files.write(Path.of(path, rule.name() + ".sql"), codeGen.getBytes());
} catch (IOException ioe) {
System.err.println(ioe.getMessage());
}
}

}