feat: parse MySQL SHOW FULL COLUMNS, SHOW TABLE STATUS and SHOW CREATE statements (#2824)

MySQL tools read table and column definitions and comments with
SHOW FULL COLUMNS, SHOW TABLE STATUS and SHOW CREATE. Only plain
SHOW COLUMNS FROM t was typed; the other forms became
UnsupportedStatement, and LIKE, WHERE or a qualified table after
SHOW COLUMNS failed to parse.

Extend ShowColumnsStatement with EXTENDED, FULL, the FIELDS spelling,
FROM/IN, a Table name, the trailing database and LIKE/WHERE, keeping
getTableName() and setTableName(String). Add ShowTableStatusStatement
and ShowCreateStatement for TABLE, VIEW, PROCEDURE, FUNCTION, TRIGGER,
EVENT, DATABASE/SCHEMA [IF NOT EXISTS] and USER, whose account reuses
MySqlAccountNamePart and accepts CURRENT_USER[()].

A typed SHOW form is chosen only when it covers the whole statement,
so other dialects' SHOW variants still fall back to
UnsupportedStatement. Wire the statements into the deparser, table
finder, validation (showTableStatus, showCreate) and feature analysis.

Signed-off-by: minleejae <mmj9808@gmail.com>

Author: minleejae

README.md

@@ -149,6 +149,7 @@ and missing syntax gets added on demand — [open an issue](https://github.com/J
 | **Tablespaces** | MySQL and PostgreSQL `CREATE TABLESPACE` · `ALTER TABLESPACE` |
 | **PostgreSQL RLS** | `CREATE POLICY` · `ALTER TABLE … ENABLE`/`DISABLE`/`FORCE`/`NO FORCE ROW LEVEL SECURITY` |
 | **Routine changes** | `ALTER FUNCTION` · `ALTER PROCEDURE` · `ALTER ROUTINE` · PostgreSQL `ALTER TRIGGER` |
+| **MySQL metadata statements** | `SHOW [FULL] COLUMNS`/`FIELDS` · `SHOW TABLE STATUS` · `SHOW CREATE TABLE`/`VIEW`/`PROCEDURE`/`FUNCTION`/`TRIGGER`/`EVENT`/`DATABASE`/`USER` |
 | **Informix constraints** | `ALTER TABLE … ADD CONSTRAINT` with trailing constraint names for primary, unique, foreign and check constraints; enable with `parser.withDialect(Dialect.INFORMIX)` |
 | **Salesforce SOQL** | `INCLUDES` · `EXCLUDES` |
 

src/main/java/net/sf/jsqlparser/parser/feature/Feature.java

@@ -736,6 +736,18 @@ public enum Feature {
      * @see ShowIndexStatement
      */
     showIndex,
+    /**
+     * MySQL/MariaDB "SHOW TABLE STATUS" statement is allowed
+     *
+     * @see ShowTableStatusStatement
+     */
+    showTableStatus,
+    /**
+     * MySQL/MariaDB "SHOW CREATE" statement is allowed
+     *
+     * @see ShowCreateStatement
+     */
+    showCreate,
     /**
      * @see UseStatement
      */

src/main/java/net/sf/jsqlparser/statement/ShowColumnsStatement.java

@@ -9,29 +9,148 @@
  */
 package net.sf.jsqlparser.statement;
 
+import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.schema.Table;
+import net.sf.jsqlparser.statement.show.ShowTablesStatement.SelectionMode;
+
+/**
+ * A MySQL {@code SHOW [EXTENDED] [FULL] {COLUMNS | FIELDS} {FROM | IN} table [{FROM | IN} db]
+ * [LIKE 'pattern' | WHERE expr]} statement.
+ *
+ * @see <a href="https://dev.mysql.com/doc/refman/8.4/en/show-columns.html">MySQL SHOW COLUMNS</a>
+ */
 public class ShowColumnsStatement implements Statement {
 
-    private String tableName;
+    private boolean extended;
+    private boolean full;
+    private boolean fieldsKeyword;
+    private SelectionMode tableSelectionMode = SelectionMode.FROM;
+    private Table table;
+    private SelectionMode dbSelectionMode = SelectionMode.FROM;
+    private String dbName;
+    private Expression likeExpression;
+    private Expression whereCondition;
 
     public ShowColumnsStatement() {
         // empty constructor
     }
 
     public ShowColumnsStatement(String tableName) {
-        this.tableName = tableName;
+        setTableName(tableName);
+    }
+
+    public ShowColumnsStatement(Table table) {
+        this.table = table;
+    }
+
+    public boolean isExtended() {
+        return extended;
+    }
+
+    public void setExtended(boolean extended) {
+        this.extended = extended;
+    }
+
+    public boolean isFull() {
+        return full;
+    }
+
+    public void setFull(boolean full) {
+        this.full = full;
+    }
+
+    /** Whether the statement is spelled with {@code FIELDS} instead of {@code COLUMNS}. */
+    public boolean isFieldsKeyword() {
+        return fieldsKeyword;
+    }
+
+    public void setFieldsKeyword(boolean fieldsKeyword) {
+        this.fieldsKeyword = fieldsKeyword;
+    }
+
+    /** The keyword before the table name, {@code FROM} unless {@code IN} was written. */
+    public SelectionMode getTableSelectionMode() {
+        return tableSelectionMode;
+    }
+
+    public void setTableSelectionMode(SelectionMode tableSelectionMode) {
+        this.tableSelectionMode = tableSelectionMode;
+    }
+
+    public Table getTable() {
+        return table;
     }
 
+    public void setTable(Table table) {
+        this.table = table;
+    }
+
+    /** The table name as written, including any qualifier; derived from {@link #getTable()}. */
     public String getTableName() {
-        return tableName;
+        return table == null ? null : table.getFullyQualifiedName();
     }
 
     public void setTableName(String tableName) {
-        this.tableName = tableName;
+        this.table = tableName == null ? null : new Table(tableName);
+    }
+
+    /** The keyword before the database name, {@code FROM} unless {@code IN} was written. */
+    public SelectionMode getDbSelectionMode() {
+        return dbSelectionMode;
+    }
+
+    public void setDbSelectionMode(SelectionMode dbSelectionMode) {
+        this.dbSelectionMode = dbSelectionMode;
+    }
+
+    /** The database of the trailing {@code FROM db} or {@code IN db} clause, or null. */
+    public String getDbName() {
+        return dbName;
+    }
+
+    public void setDbName(String dbName) {
+        this.dbName = dbName;
+    }
+
+    public Expression getLikeExpression() {
+        return likeExpression;
+    }
+
+    public void setLikeExpression(Expression likeExpression) {
+        this.likeExpression = likeExpression;
+    }
+
+    public Expression getWhereCondition() {
+        return whereCondition;
+    }
+
+    public void setWhereCondition(Expression whereCondition) {
+        this.whereCondition = whereCondition;
     }
 
     @Override
     public String toString() {
-        return "SHOW COLUMNS FROM " + tableName;
+        StringBuilder builder = new StringBuilder("SHOW");
+        if (extended) {
+            builder.append(" EXTENDED");
+        }
+        if (full) {
+            builder.append(" FULL");
+        }
+        builder.append(fieldsKeyword ? " FIELDS " : " COLUMNS ")
+                .append(tableSelectionMode == null ? SelectionMode.FROM : tableSelectionMode)
+                .append(' ').append(table);
+        if (dbName != null) {
+            builder.append(' ')
+                    .append(dbSelectionMode == null ? SelectionMode.FROM : dbSelectionMode)
+                    .append(' ').append(dbName);
+        }
+        if (likeExpression != null) {
+            builder.append(" LIKE ").append(likeExpression);
+        } else if (whereCondition != null) {
+            builder.append(" WHERE ").append(whereCondition);
+        }
+        return builder.toString();
     }
 
     @Override
@@ -43,4 +162,49 @@ public ShowColumnsStatement withTableName(String tableName) {
         this.setTableName(tableName);
         return this;
     }
+
+    public ShowColumnsStatement withTable(Table table) {
+        this.setTable(table);
+        return this;
+    }
+
+    public ShowColumnsStatement withExtended(boolean extended) {
+        this.setExtended(extended);
+        return this;
+    }
+
+    public ShowColumnsStatement withFull(boolean full) {
+        this.setFull(full);
+        return this;
+    }
+
+    public ShowColumnsStatement withFieldsKeyword(boolean fieldsKeyword) {
+        this.setFieldsKeyword(fieldsKeyword);
+        return this;
+    }
+
+    public ShowColumnsStatement withTableSelectionMode(SelectionMode tableSelectionMode) {
+        this.setTableSelectionMode(tableSelectionMode);
+        return this;
+    }
+
+    public ShowColumnsStatement withDbSelectionMode(SelectionMode dbSelectionMode) {
+        this.setDbSelectionMode(dbSelectionMode);
+        return this;
+    }
+
+    public ShowColumnsStatement withDbName(String dbName) {
+        this.setDbName(dbName);
+        return this;
+    }
+
+    public ShowColumnsStatement withLikeExpression(Expression likeExpression) {
+        this.setLikeExpression(likeExpression);
+        return this;
+    }
+
+    public ShowColumnsStatement withWhereCondition(Expression whereCondition) {
+        this.setWhereCondition(whereCondition);
+        return this;
+    }
 }

src/main/java/net/sf/jsqlparser/statement/StatementFeatureVisitor.java

@@ -116,7 +116,9 @@
 import net.sf.jsqlparser.statement.select.SelectVisitorAdapter;
 import net.sf.jsqlparser.statement.select.TableStatement;
 import net.sf.jsqlparser.statement.select.WithItem;
+import net.sf.jsqlparser.statement.show.ShowCreateStatement;
 import net.sf.jsqlparser.statement.show.ShowIndexStatement;
+import net.sf.jsqlparser.statement.show.ShowTableStatusStatement;
 import net.sf.jsqlparser.statement.show.ShowTablesStatement;
 import net.sf.jsqlparser.statement.truncate.Truncate;
 import net.sf.jsqlparser.statement.update.Update;
@@ -940,6 +942,16 @@ public <S> Void visit(ShowTablesStatement showTables, S context) {
         return metadataOnly();
     }
 
+    @Override
+    public <S> Void visit(ShowTableStatusStatement showTableStatus, S context) {
+        return metadataOnly();
+    }
+
+    @Override
+    public <S> Void visit(ShowCreateStatement showCreate, S context) {
+        return metadataOnly();
+    }
+
     @Override
     public <S> Void visit(DescribeStatement describe, S context) {
         return metadataOnly();

src/main/java/net/sf/jsqlparser/statement/StatementVisitor.java

@@ -91,7 +91,9 @@
 import net.sf.jsqlparser.statement.merge.Merge;
 import net.sf.jsqlparser.statement.refresh.RefreshMaterializedViewStatement;
 import net.sf.jsqlparser.statement.select.Select;
+import net.sf.jsqlparser.statement.show.ShowCreateStatement;
 import net.sf.jsqlparser.statement.show.ShowIndexStatement;
+import net.sf.jsqlparser.statement.show.ShowTableStatusStatement;
 import net.sf.jsqlparser.statement.show.ShowTablesStatement;
 import net.sf.jsqlparser.statement.truncate.Truncate;
 import net.sf.jsqlparser.statement.update.ParenthesedUpdate;
@@ -366,6 +368,22 @@ default void visit(ShowTablesStatement showTables) {
         this.visit(showTables, null);
     }
 
+    default <S> T visit(ShowTableStatusStatement showTableStatus, S context) {
+        return null;
+    }
+
+    default void visit(ShowTableStatusStatement showTableStatus) {
+        this.visit(showTableStatus, null);
+    }
+
+    default <S> T visit(ShowCreateStatement showCreate, S context) {
+        return null;
+    }
+
+    default void visit(ShowCreateStatement showCreate) {
+        this.visit(showCreate, null);
+    }
+
     <S> T visit(Merge merge, S context);
 
     default void visit(Merge merge) {

src/main/java/net/sf/jsqlparser/statement/StatementVisitorAdapter.java

@@ -105,7 +105,9 @@
 import net.sf.jsqlparser.statement.select.SelectVisitor;
 import net.sf.jsqlparser.statement.select.SelectVisitorAdapter;
 import net.sf.jsqlparser.statement.select.WithItem;
+import net.sf.jsqlparser.statement.show.ShowCreateStatement;
 import net.sf.jsqlparser.statement.show.ShowIndexStatement;
+import net.sf.jsqlparser.statement.show.ShowTableStatusStatement;
 import net.sf.jsqlparser.statement.show.ShowTablesStatement;
 import net.sf.jsqlparser.statement.truncate.Truncate;
 import net.sf.jsqlparser.statement.update.ParenthesedUpdate;
@@ -604,6 +606,16 @@ public <S> T visit(ShowTablesStatement showTables, S context) {
         return null;
     }
 
+    @Override
+    public <S> T visit(ShowTableStatusStatement showTableStatus, S context) {
+        return null;
+    }
+
+    @Override
+    public <S> T visit(ShowCreateStatement showCreate, S context) {
+        return null;
+    }
+
     @Override
     public <S> T visit(DeclareStatement declareStatement, S context) {
         return null;