Add support of EXPLAIN QUERY PLAN syntax for SQLite dialect (#1458)

src/ast/mod.rs

@@ -3111,6 +3111,11 @@ pub enum Statement {
         analyze: bool,
         // Display additional information regarding the plan.
         verbose: bool,
+        /// `EXPLAIN QUERY PLAN`
+        /// Display the query plan without running the query.
+        ///
+        /// [SQLite](https://sqlite.org/lang_explain.html)
+        query_plan: bool,
         /// A SQL query that specifies what to explain
         statement: Box<Statement>,
         /// Optional output format of explain
@@ -3302,12 +3307,16 @@ impl fmt::Display for Statement {
                 describe_alias,
                 verbose,
                 analyze,
+                query_plan,
                 statement,
                 format,
                 options,
             } => {
                 write!(f, "{describe_alias} ")?;
 
+                if *query_plan {
+                    write!(f, "QUERY PLAN ")?;
+                }
                 if *analyze {
                     write!(f, "ANALYZE ")?;
                 }

src/keywords.rs

@@ -572,6 +572,7 @@ define_keywords!(
     PERSISTENT,
     PIVOT,
     PLACING,
+    PLAN,
     PLANS,
     POLICY,
     PORTION,

src/parser/mod.rs

@@ -8662,6 +8662,7 @@ impl<'a> Parser<'a> {
     ) -> Result<Statement, ParserError> {
         let mut analyze = false;
         let mut verbose = false;
+        let mut query_plan = false;
         let mut format = None;
         let mut options = None;
 
@@ -8672,6 +8673,8 @@ impl<'a> Parser<'a> {
             && self.peek_token().token == Token::LParen
         {
             options = Some(self.parse_utility_options()?)
+        } else if self.parse_keywords(&[Keyword::QUERY, Keyword::PLAN]) {
+            query_plan = true;
         } else {
             analyze = self.parse_keyword(Keyword::ANALYZE);
             verbose = self.parse_keyword(Keyword::VERBOSE);
@@ -8688,6 +8691,7 @@ impl<'a> Parser<'a> {
                 describe_alias,
                 analyze,
                 verbose,
+                query_plan,
                 statement: Box::new(statement),
                 format,
                 options,