Add support for Snowflake SHOW DATABASES/SCHEMAS/TABLES/VIEWS/COLUMNS statements (#1501)

Author: yoavcloud

src/ast/mod.rs

@@ -2773,41 +2773,45 @@ pub enum Statement {
     /// ```sql
     /// SHOW COLUMNS
     /// ```
-    ///
-    /// Note: this is a MySQL-specific statement.
     ShowColumns {
         extended: bool,
         full: bool,
-        #[cfg_attr(feature = "visitor", visit(with = "visit_relation"))]
-        table_name: ObjectName,
-        filter: Option<ShowStatementFilter>,
+        show_options: ShowStatementOptions,
     },
     /// ```sql
-    /// SHOW DATABASES [LIKE 'pattern']
+    /// SHOW DATABASES
     /// ```
-    ShowDatabases { filter: Option<ShowStatementFilter> },
+    ShowDatabases {
+        terse: bool,
+        history: bool,
+        show_options: ShowStatementOptions,
+    },
     /// ```sql
-    /// SHOW SCHEMAS [LIKE 'pattern']
+    /// SHOW SCHEMAS
     /// ```
-    ShowSchemas { filter: Option<ShowStatementFilter> },
+    ShowSchemas {
+        terse: bool,
+        history: bool,
+        show_options: ShowStatementOptions,
+    },
     /// ```sql
     /// SHOW TABLES
     /// ```
     ShowTables {
+        terse: bool,
+        history: bool,
         extended: bool,
         full: bool,
-        clause: Option<ShowClause>,
-        db_name: Option<Ident>,
-        filter: Option<ShowStatementFilter>,
+        external: bool,
+        show_options: ShowStatementOptions,
     },
     /// ```sql
     /// SHOW VIEWS
     /// ```
     ShowViews {
+        terse: bool,
         materialized: bool,
-        clause: Option<ShowClause>,
-        db_name: Option<Ident>,
-        filter: Option<ShowStatementFilter>,
+        show_options: ShowStatementOptions,
     },
     /// ```sql
     /// SHOW COLLATION
@@ -4387,79 +4391,72 @@ impl fmt::Display for Statement {
             Statement::ShowColumns {
                 extended,
                 full,
-                table_name,
-                filter,
+                show_options,
             } => {
                 write!(
                     f,
-                    "SHOW {extended}{full}COLUMNS FROM {table_name}",
+                    "SHOW {extended}{full}COLUMNS{show_options}",
                     extended = if *extended { "EXTENDED " } else { "" },
                     full = if *full { "FULL " } else { "" },
-                    table_name = table_name,
                 )?;
-                if let Some(filter) = filter {
-                    write!(f, " {filter}")?;
-                }
                 Ok(())
             }
-            Statement::ShowDatabases { filter } => {
-                write!(f, "SHOW DATABASES")?;
-                if let Some(filter) = filter {
-                    write!(f, " {filter}")?;
-                }
+            Statement::ShowDatabases {
+                terse,
+                history,
+                show_options,
+            } => {
+                write!(
+                    f,
+                    "SHOW {terse}DATABASES{history}{show_options}",
+                    terse = if *terse { "TERSE " } else { "" },
+                    history = if *history { " HISTORY" } else { "" },
+                )?;
                 Ok(())
             }
-            Statement::ShowSchemas { filter } => {
-                write!(f, "SHOW SCHEMAS")?;
-                if let Some(filter) = filter {
-                    write!(f, " {filter}")?;
-                }
+            Statement::ShowSchemas {
+                terse,
+                history,
+                show_options,
+            } => {
+                write!(
+                    f,
+                    "SHOW {terse}SCHEMAS{history}{show_options}",
+                    terse = if *terse { "TERSE " } else { "" },
+                    history = if *history { " HISTORY" } else { "" },
+                )?;
                 Ok(())
             }
             Statement::ShowTables {
+                terse,
+                history,
                 extended,
                 full,
-                clause: show_clause,
-                db_name,
-                filter,
+                external,
+                show_options,
             } => {
                 write!(
                     f,
-                    "SHOW {extended}{full}TABLES",
+                    "SHOW {terse}{extended}{full}{external}TABLES{history}{show_options}",
+                    terse = if *terse { "TERSE " } else { "" },
                     extended = if *extended { "EXTENDED " } else { "" },
                     full = if *full { "FULL " } else { "" },
+                    external = if *external { "EXTERNAL " } else { "" },
+                    history = if *history { " HISTORY" } else { "" },
                 )?;
-                if let Some(show_clause) = show_clause {
-                    write!(f, " {show_clause}")?;
-                }
-                if let Some(db_name) = db_name {
-                    write!(f, " {db_name}")?;
-                }
-                if let Some(filter) = filter {
-                    write!(f, " {filter}")?;
-                }
                 Ok(())
             }
             Statement::ShowViews {
+                terse,
                 materialized,
-                clause: show_clause,
-                db_name,
-                filter,
+                show_options,
             } => {
                 write!(
                     f,
-                    "SHOW {}VIEWS",
-                    if *materialized { "MATERIALIZED " } else { "" }
+                    "SHOW {terse}{materialized}VIEWS{show_options}",
+                    terse = if *terse { "TERSE " } else { "" },
+                    materialized = if *materialized { "MATERIALIZED " } else { "" }
                 )?;
-                if let Some(show_clause) = show_clause {
-                    write!(f, " {show_clause}")?;
-                }
-                if let Some(db_name) = db_name {
-                    write!(f, " {db_name}")?;
-                }
-                if let Some(filter) = filter {
-                    write!(f, " {filter}")?;
-                }
                 Ok(())
             }
             Statement::ShowFunctions { filter } => {
@@ -6172,14 +6169,14 @@ impl fmt::Display for ShowStatementFilter {
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
-pub enum ShowClause {
+pub enum ShowStatementInClause {
     IN,
     FROM,
 }
 
-impl fmt::Display for ShowClause {
+impl fmt::Display for ShowStatementInClause {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        use ShowClause::*;
+        use ShowStatementInClause::*;
         match self {
             FROM => write!(f, "FROM"),
             IN => write!(f, "IN"),
@@ -7357,6 +7354,108 @@ impl Display for UtilityOption {
     }
 }
 
+/// Represents the different options available for `SHOW`
+/// statements to filter the results. Example from Snowflake:
+/// <https://docs.snowflake.com/en/sql-reference/sql/show-tables>
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct ShowStatementOptions {
+    pub show_in: Option<ShowStatementIn>,
+    pub starts_with: Option<Value>,
+    pub limit: Option<Expr>,
+    pub limit_from: Option<Value>,
+    pub filter_position: Option<ShowStatementFilterPosition>,
+}
+
+impl Display for ShowStatementOptions {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let (like_in_infix, like_in_suffix) = match &self.filter_position {
+            Some(ShowStatementFilterPosition::Infix(filter)) => {
+                (format!(" {filter}"), "".to_string())
+            }
+            Some(ShowStatementFilterPosition::Suffix(filter)) => {
+                ("".to_string(), format!(" {filter}"))
+            }
+            None => ("".to_string(), "".to_string()),
+        };
+        write!(
+            f,
+            "{like_in_infix}{show_in}{starts_with}{limit}{from}{like_in_suffix}",
+            show_in = match &self.show_in {
+                Some(i) => format!(" {i}"),
+                None => String::new(),
+            },
+            starts_with = match &self.starts_with {
+                Some(s) => format!(" STARTS WITH {s}"),
+                None => String::new(),
+            },
+            limit = match &self.limit {
+                Some(l) => format!(" LIMIT {l}"),
+                None => String::new(),
+            },
+            from = match &self.limit_from {
+                Some(f) => format!(" FROM {f}"),
+                None => String::new(),
+            }
+        )?;
+        Ok(())
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum ShowStatementFilterPosition {
+    Infix(ShowStatementFilter), // For example: SHOW COLUMNS LIKE '%name%' IN TABLE tbl
+    Suffix(ShowStatementFilter), // For example: SHOW COLUMNS IN tbl LIKE '%name%'
+}
+
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum ShowStatementInParentType {
+    Account,
+    Database,
+    Schema,
+    Table,
+    View,
+}
+
+impl fmt::Display for ShowStatementInParentType {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            ShowStatementInParentType::Account => write!(f, "ACCOUNT"),
+            ShowStatementInParentType::Database => write!(f, "DATABASE"),
+            ShowStatementInParentType::Schema => write!(f, "SCHEMA"),
+            ShowStatementInParentType::Table => write!(f, "TABLE"),
+            ShowStatementInParentType::View => write!(f, "VIEW"),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct ShowStatementIn {
+    pub clause: ShowStatementInClause,
+    pub parent_type: Option<ShowStatementInParentType>,
+    pub parent_name: Option<ObjectName>,
+}
+
+impl fmt::Display for ShowStatementIn {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.clause)?;
+        if let Some(parent_type) = &self.parent_type {
+            write!(f, " {}", parent_type)?;
+        }
+        if let Some(parent_name) = &self.parent_name {
+            write!(f, " {}", parent_name)?;
+        }
+        Ok(())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/dialect/mod.rs

@@ -622,6 +622,12 @@ pub trait Dialect: Debug + Any {
     fn supports_boolean_literals(&self) -> bool {
         true
     }
+
+    /// Returns true if this dialect supports the `LIKE 'pattern'` option in
+    /// a `SHOW` statement before the `IN` option
+    fn supports_show_like_before_in(&self) -> bool {
+        false
+    }
 }
 
 /// This represents the operators for which precedence must be defined

src/dialect/snowflake.rs

@@ -203,6 +203,12 @@ impl Dialect for SnowflakeDialect {
     fn allow_extract_single_quotes(&self) -> bool {
         true
     }
+
+    /// Snowflake expects the `LIKE` option before the `IN` option,
+    /// for example: <https://docs.snowflake.com/en/sql-reference/sql/show-views#syntax>
+    fn supports_show_like_before_in(&self) -> bool {
+        true
+    }
 }
 
 /// Parse snowflake create table statement.

src/keywords.rs

@@ -76,6 +76,7 @@ define_keywords!(
     ABS,
     ABSOLUTE,
     ACCESS,
+    ACCOUNT,
     ACTION,
     ADD,
     ADMIN,
@@ -91,6 +92,7 @@ define_keywords!(
     AND,
     ANTI,
     ANY,
+    APPLICATION,
     APPLY,
     ARCHIVE,
     ARE,
@@ -710,6 +712,7 @@ define_keywords!(
     STABLE,
     STAGE,
     START,
+    STARTS,
     STATEMENT,
     STATIC,
     STATISTICS,
@@ -746,6 +749,7 @@ define_keywords!(
     TEMP,
     TEMPORARY,
     TERMINATED,
+    TERSE,
     TEXT,
     TEXTFILE,
     THEN,