feat: support HTTP&gRPC&pg set timezone (#3125)

* feat: support HTTP&gRPC&pg set timezone

* chore: fix code advice

* chore: fix code advice

src/sql/src/parser.rs

@@ -117,6 +117,8 @@ impl<'a> ParserContext<'a> {
 
                     Keyword::TRUNCATE => self.parse_truncate(),
 
+                    Keyword::SET => self.parse_set_variables(),
+
                     Keyword::NoKeyword
                         if w.value.to_uppercase() == tql_parser::TQL && w.quote_style.is_none() =>
                     {

src/sql/src/parsers.rs

@@ -21,6 +21,7 @@ pub(crate) mod drop_parser;
 pub(crate) mod explain_parser;
 pub(crate) mod insert_parser;
 pub(crate) mod query_parser;
+pub(crate) mod set_var_parser;
 pub(crate) mod show_parser;
 pub(crate) mod tql_parser;
 pub(crate) mod truncate_parser;

src/sql/src/parsers/set_var_parser.rs

@@ -0,0 +1,78 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use snafu::ResultExt;
+use sqlparser::ast::Statement as SpStatement;
+
+use crate::error::{self, Result};
+use crate::parser::ParserContext;
+use crate::statements::set_variables::SetVariables;
+use crate::statements::statement::Statement;
+
+/// SET variables statement parser implementation
+impl<'a> ParserContext<'a> {
+    pub(crate) fn parse_set_variables(&mut self) -> Result<Statement> {
+        let _ = self.parser.next_token();
+        let spstatement = self.parser.parse_set().context(error::SyntaxSnafu)?;
+        match spstatement {
+            SpStatement::SetVariable {
+                variable,
+                value,
+                local,
+                hivevar,
+            } if !local && !hivevar => {
+                Ok(Statement::SetVariables(SetVariables { variable, value }))
+            }
+            unexp => error::UnsupportedSnafu {
+                sql: self.sql.to_string(),
+                keyword: unexp.to_string(),
+            }
+            .fail(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use sqlparser::ast::{Expr, Ident, ObjectName, Value};
+
+    use super::*;
+    use crate::dialect::GreptimeDbDialect;
+
+    #[test]
+    pub fn test_set_timezone() {
+        // mysql style
+        let sql = "SET time_zone = 'UTC'";
+        let result = ParserContext::create_with_dialect(sql, &GreptimeDbDialect {});
+        let mut stmts = result.unwrap();
+        assert_eq!(
+            stmts.pop().unwrap(),
+            Statement::SetVariables(SetVariables {
+                variable: ObjectName(vec![Ident::new("time_zone")]),
+                value: vec![Expr::Value(Value::SingleQuotedString("UTC".to_string()))]
+            })
+        );
+        // postgresql style
+        let sql = "SET TIMEZONE TO 'UTC'";
+        let result = ParserContext::create_with_dialect(sql, &GreptimeDbDialect {});
+        let mut stmts = result.unwrap();
+        assert_eq!(
+            stmts.pop().unwrap(),
+            Statement::SetVariables(SetVariables {
+                variable: ObjectName(vec![Ident::new("TIMEZONE")]),
+                value: vec![Expr::Value(Value::SingleQuotedString("UTC".to_string()))],
+            })
+        );
+    }
+}

src/sql/src/parsers/show_parser.rs

@@ -18,7 +18,9 @@ use sqlparser::tokenizer::Token;
 
 use crate::error::{self, InvalidDatabaseNameSnafu, InvalidTableNameSnafu, Result};
 use crate::parser::ParserContext;
-use crate::statements::show::{ShowCreateTable, ShowDatabases, ShowKind, ShowTables};
+use crate::statements::show::{
+    ShowCreateTable, ShowDatabases, ShowKind, ShowTables, ShowVariables,
+};
 use crate::statements::statement::Statement;
 
 /// SHOW statement parser implementation
@@ -43,6 +45,16 @@ impl<'a> ParserContext<'a> {
             } else {
                 self.unsupported(self.peek_token_as_string())
             }
+        } else if self.consume_token("VARIABLES") {
+            let variable =
+                self.parser
+                    .parse_object_name()
+                    .with_context(|_| error::UnexpectedSnafu {
+                        sql: self.sql,
+                        expected: "a variable name",
+                        actual: self.peek_token_as_string(),
+                    })?;
+            Ok(Statement::ShowVariables(ShowVariables { variable }))
         } else {
             self.unsupported(self.peek_token_as_string())
         }
@@ -178,6 +190,8 @@ impl<'a> ParserContext<'a> {
 mod tests {
     use std::assert_matches::assert_matches;
 
+    use sqlparser::ast::{Ident, ObjectName};
+
     use super::*;
     use crate::dialect::GreptimeDbDialect;
     use crate::statements::show::ShowDatabases;
@@ -387,4 +401,18 @@ mod tests {
             })
         );
     }
+
+    #[test]
+    pub fn test_show_variables() {
+        let sql = "SHOW VARIABLES system_time_zone";
+        let result = ParserContext::create_with_dialect(sql, &GreptimeDbDialect {});
+        let stmts = result.unwrap();
+        assert_eq!(1, stmts.len());
+        assert_eq!(
+            stmts[0],
+            Statement::ShowVariables(ShowVariables {
+                variable: ObjectName(vec![Ident::new("system_time_zone")]),
+            })
+        );
+    }
 }

src/sql/src/statements.rs

@@ -22,6 +22,7 @@ pub mod explain;
 pub mod insert;
 mod option_map;
 pub mod query;
+pub mod set_variables;
 pub mod show;
 pub mod statement;
 pub mod tql;
@@ -505,7 +506,7 @@ pub fn sql_location_to_grpc_add_column_location(
     match location {
         Some(AddColumnLocation::First) => Some(Location {
             location_type: LocationType::First.into(),
-            after_column_name: "".to_string(),
+            after_column_name: String::default(),
         }),
         Some(AddColumnLocation::After { column_name }) => Some(Location {
             location_type: LocationType::After.into(),

src/sql/src/statements/create.rs

@@ -96,7 +96,7 @@ impl CreateTable {
         if let Some(partitions) = &self.partitions {
             format!("{}\n", partitions)
         } else {
-            "".to_string()
+            String::default()
         }
     }
 
@@ -112,7 +112,7 @@ impl CreateTable {
     #[inline]
     fn format_options(&self) -> String {
         if self.options.is_empty() {
-            "".to_string()
+            String::default()
         } else {
             let options: Vec<&SqlOption> = self.options.iter().sorted().collect();
             let options = format_list_indent!(options);

src/sql/src/statements/set_variables.rs

@@ -0,0 +1,23 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use sqlparser::ast::{Expr, ObjectName};
+use sqlparser_derive::{Visit, VisitMut};
+
+/// SET variables statement.
+#[derive(Debug, Clone, PartialEq, Eq, Visit, VisitMut)]
+pub struct SetVariables {
+    pub variable: ObjectName,
+    pub value: Vec<Expr>,
+}

src/sql/src/statements/show.rs

@@ -63,6 +63,12 @@ pub struct ShowCreateTable {
     pub table_name: ObjectName,
 }
 
+/// SQL structure for `SHOW VARIABLES xxx`.
+#[derive(Debug, Clone, PartialEq, Eq, Visit, VisitMut)]
+pub struct ShowVariables {
+    pub variable: ObjectName,
+}
+
 #[cfg(test)]
 mod tests {
     use std::assert_matches::assert_matches;

src/sql/src/statements/statement.rs

@@ -16,6 +16,7 @@ use datafusion_sql::parser::Statement as DfStatement;
 use sqlparser::ast::Statement as SpStatement;
 use sqlparser_derive::{Visit, VisitMut};
 
+use super::show::ShowVariables;
 use crate::error::{ConvertToDfStatementSnafu, Error};
 use crate::statements::alter::AlterTable;
 use crate::statements::create::{CreateDatabase, CreateExternalTable, CreateTable};
@@ -25,6 +26,7 @@ use crate::statements::drop::DropTable;
 use crate::statements::explain::Explain;
 use crate::statements::insert::Insert;
 use crate::statements::query::Query;
+use crate::statements::set_variables::SetVariables;
 use crate::statements::show::{ShowCreateTable, ShowDatabases, ShowTables};
 use crate::statements::tql::Tql;
 use crate::statements::truncate::TruncateTable;
@@ -64,6 +66,10 @@ pub enum Statement {
     Tql(Tql),
     // TRUNCATE TABLE
     TruncateTable(TruncateTable),
+    // SET VARIABLES
+    SetVariables(SetVariables),
+    // SHOW VARIABLES
+    ShowVariables(ShowVariables),
 }
 
 /// Comment hints from SQL.