Allow a prepared Statement to be called like a function

docs/src/index.md

@@ -26,6 +26,14 @@ async_result = async_execute(conn, "SELECT typname FROM pg_type WHERE oid = \$1"
 result = fetch(async_result)
 data = columntable(result)
 
+# the same but with prepared statements
+stmt = prepare(conn, "SELECT typname FROM pg_type WHERE oid = \$1")
+result = execute(stmt, ["16"])
+data = columntable(result)
+# or
+result = stmt("16")
+data = columntable(result)
+
 close(conn)
 ```
 

src/statements.jl

@@ -27,6 +27,8 @@ Base.broadcastable(stmt::Statement) = Ref(stmt)
 Create a prepared statement on the PostgreSQL server using libpq.
 The statement is given an generated unique name using [`unique_id`](@ref).
 
+Statements are executable either via `execute(stmt, args...; kwargs...)` or `stmt(args...; kwargs...)`
+
 !!! note
 
     Currently the statement is not explicitly deallocated, but it is deallocated at the end
@@ -159,3 +161,15 @@ function _execute_prepared(
         zero(Cint),  # return result in text format
     )
 end
+
+function (stmt::Statement)(; kwargs...)
+    execute(stmt; kwargs...)
+end
+
+function (stmt::Statement)(parameters::Union{AbstractVector, Tuple}; kwargs...)
+    execute(stmt, parameters; kwargs...)
+end
+
+function (stmt::Statement)(parameters...; kwargs...)
+    execute(stmt, parameters; kwargs...)
+end

test/runtests.jl

@@ -1487,15 +1487,21 @@ end
             @test LibPQ.num_columns(stmt) == 2
             @test LibPQ.num_params(stmt) == 0
             @test LibPQ.column_names(stmt) == ["oid", "typname"]
+
+            function _test_stmt_exec_1(result)
+                @test LibPQ.num_columns(result) == 2
+                @test LibPQ.column_names(result) == ["oid", "typname"]
+                @test LibPQ.column_types(result) == [LibPQ.Oid, String]
+                @test LibPQ.num_rows(result) > 0
 
-            result = execute(stmt; throw_error=true)
+                close(result)
+            end
 
-            @test LibPQ.num_columns(result) == 2
-            @test LibPQ.column_names(result) == ["oid", "typname"]
-            @test LibPQ.column_types(result) == [LibPQ.Oid, String]
-            @test LibPQ.num_rows(result) > 0
+            result = execute(stmt; throw_error=true)
+            _test_stmt_exec_1(result)
 
-            close(result)
+            result = stmt(; throw_error=true)
+            _test_stmt_exec_1(result)
 
             close(conn)
         end
@@ -1508,19 +1514,28 @@ end
             @test LibPQ.num_columns(stmt) == 2
             @test LibPQ.num_params(stmt) == 1
             @test LibPQ.column_names(stmt) == ["oid", "typname"]
+
+            function _test_stmt_exec_2(result)
+                @test LibPQ.num_columns(result) == 2
+                @test LibPQ.column_names(result) == ["oid", "typname"]
+                @test LibPQ.column_types(result) == [LibPQ.Oid, String]
+                @test LibPQ.num_rows(result) == 1
 
-            result = execute(stmt, [16]; throw_error=true)
+                data = columntable(result)
+                @test data[:oid][1] == 16
+                @test data[:typname][1] == "bool"
 
-            @test LibPQ.num_columns(result) == 2
-            @test LibPQ.column_names(result) == ["oid", "typname"]
-            @test LibPQ.column_types(result) == [LibPQ.Oid, String]
-            @test LibPQ.num_rows(result) == 1
+                close(result)
+            end
 
-            data = columntable(result)
-            @test data[:oid][1] == 16
-            @test data[:typname][1] == "bool"
+            result = execute(stmt, [16]; throw_error=true)
+            _test_stmt_exec_2(result)
 
-            close(result)
+            result = stmt([16]; throw_error=true)
+            _test_stmt_exec_2(result)
+
+            result = stmt(16; throw_error=true)
+            _test_stmt_exec_2(result)
 
             close(conn)
         end