risingwave_frontend/handler/
drop_function.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use super::*;
16use crate::catalog::CatalogError;
17use crate::catalog::root_catalog::SchemaPath;
18use crate::{Binder, bind_data_type};
19
20/// Drop a function or an aggregate.
21pub async fn handle_drop_function(
22    handler_args: HandlerArgs,
23    if_exists: bool,
24    mut func_desc: Vec<FunctionDesc>,
25    _option: Option<ReferentialAction>,
26    aggregate: bool,
27) -> Result<RwPgResponse> {
28    if func_desc.len() != 1 {
29        bail_not_implemented!("only support dropping 1 function");
30    }
31    let stmt_type = if aggregate {
32        StatementType::DROP_AGGREGATE
33    } else {
34        StatementType::DROP_FUNCTION
35    };
36    let func_desc = func_desc.remove(0);
37
38    let session = handler_args.session;
39    let db_name = &session.database();
40    let (schema_name, function_name) =
41        Binder::resolve_schema_qualified_name(db_name, func_desc.name)?;
42    let search_path = session.config().search_path();
43    let user_name = &session.user_name();
44    let schema_path = SchemaPath::new(schema_name.as_deref(), &search_path, user_name);
45
46    let arg_types = match func_desc.args {
47        Some(args) => {
48            let mut arg_types = vec![];
49            for arg in args {
50                arg_types.push(bind_data_type(&arg.data_type)?);
51            }
52            Some(arg_types)
53        }
54        None => None,
55    };
56
57    let function_id = {
58        let reader = session.env().catalog_reader().read_guard();
59        let res = match arg_types {
60            Some(arg_types) => {
61                reader.get_function_by_name_args(db_name, schema_path, &function_name, &arg_types)
62            }
63            // check if there is only one function if arguments are not specified
64            None => match reader.get_functions_by_name(db_name, schema_path, &function_name) {
65                Ok((functions, schema_name)) => {
66                    if functions.len() > 1 {
67                        return Err(ErrorCode::CatalogError(format!("function name {function_name:?} is not unique\nHINT: Specify the argument list to select the function unambiguously.").into()).into());
68                    }
69                    Ok((
70                        functions.into_iter().next().expect("no functions"),
71                        schema_name,
72                    ))
73                }
74                Err(e) => Err(e),
75            },
76        };
77        match res {
78            Ok((function, schema_name)) => {
79                session.check_privilege_for_drop_alter(schema_name, &**function)?;
80                if !aggregate && function.kind.is_aggregate() {
81                    return Err(ErrorCode::CatalogError(
82                        format!("\"{function_name}\" is an aggregate function\nHINT:  Use DROP AGGREGATE to drop aggregate functions.").into(),
83                    )
84                    .into());
85                } else if aggregate && !function.kind.is_aggregate() {
86                    return Err(ErrorCode::CatalogError(
87                        format!("\"{function_name}\" is not an aggregate").into(),
88                    )
89                    .into());
90                }
91                function.id
92            }
93            Err(CatalogError::NotFound(kind, _)) if kind == "function" && if_exists => {
94                return Ok(RwPgResponse::builder(stmt_type)
95                    .notice(format!(
96                        "function \"{}\" does not exist, skipping",
97                        function_name
98                    ))
99                    .into());
100            }
101            Err(e) => return Err(e.into()),
102        }
103    };
104
105    let catalog_writer = session.catalog_writer()?;
106    catalog_writer.drop_function(function_id).await?;
107
108    Ok(PgResponse::empty_result(stmt_type))
109}
risingwave_frontend/handler/drop_function.rs

risingwave_frontend/handler/
drop_function.rs
