initial commit

.gitignore

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+.gradle
+/build/
+
+# Ignore Gradle GUI config
+gradle-app.setting
+
+# Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
+!gradle-wrapper.jar
+
+# Cache of project
+.gradletasknamecache
+
+# # Work around https://youtrack.jetbrains.com/issue/IDEA-116898
+# gradle/wrapper/gradle-wrapper.properties

build.gradle

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+plugins {
+    id 'java'
+}
+
+group 'org.example'
+version '1.0-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.1'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'
+}
+
+test {
+    useJUnitPlatform()
+}

docs/mysql/syntax/ref/select_expr.md

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+## Sub syntax for select_expr
+
+`simplified version`
+```text
+select_alias:
+    /* empty */
+  | AS alias_name
+  | alias_name
+
+select_expr:
+    expr select_alias
+```
+
+## Examples
+```roomsql
+Select
+    id, name, age
+    From customer;
+```
+```roomsql
+Select
+    id 'Id', name 'Name', age 'Age'
+    From customer;
+```
+```roomsql
+Select
+    id As 'Id', name As 'Name', age As 'Age'
+    From customer;
+```

docs/mysql/syntax/ref/table_references.md

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+# Sub syntax for `table_references`
+
+`simplified version`
+```text
+table_references:
+    table_reference [, table_reference] ...
+
+table_reference: {
+    table_factor
+  | joined_table
+}
+
+table_factor: {
+    tbl_name
+        [[AS] alias]
+  | ( table_references )
+}
+
+joined_table: {
+    table_reference {[INNER | CROSS] JOIN | STRAIGHT_JOIN} table_factor [join_specification]
+  | table_reference {LEFT|RIGHT} [OUTER] JOIN table_reference join_specification
+  | table_reference NATURAL [INNER | {LEFT|RIGHT} [OUTER]] JOIN table_factor
+}
+
+join_specification: {
+    ON search_condition
+  | USING (join_column_list)
+}
+
+join_column_list:
+    column_name [, column_name] ...
+```
+
+## Examples
+`table_factor`
+```roomsql
+Select * From customer;
+```
+```roomsql
+Select * From customer cust;
+```
+```roomsql
+Select * From customer As cust;
+```
+---
+`joined_table`
+
+Inner Join with `On`
+```roomsql
+Select
+    cust.id, cust.name, cust.mail, addr.city, addr.pincode
+    From customer cust
+    Inner Join address addr
+        On cust.addr_id = addr.id;
+```
+Inner Join without `On`
+```roomsql
+Select
+    cust.id, cust.name, cust.mail, addr.city, addr.pincode
+    From customer cust
+    Inner Join address addr
+    Where cust.addr_id = addr.id;
+```
+Outer Join
+```roomsql
+Select
+    cust.id, cust.name, cust.mail, addr.city, addr.pincode
+    From customer cust
+    Left Outer Join address addr
+        On cust.addr_id = addr.id;
+```
+Natural Join
+```roomsql
+Select
+    cust.id, cust.name, cust.mail, addr.city, addr.pincode
+    From customer cust
+    Natural Inner Join address addr;
+```
+Join with `Using`
+```roomsql
+Select
+    id, name, addr_id, city
+    From customer cust
+    Inner Join address addr
+        Using (addr_id);
+```
+Inner and Outer Join
+```roomsql
+Select
+    usr.id As 'User Id', dept.id As 'Department Id', dept.name, usr.points, Count(idea.id) As 'Total Ideas'
+    From user usr
+    Inner Join department dept
+        Using (id)
+    Left Join customer_idea idea
+        On usr.id = idea.id
+    Order By idea.id;
+```