sql: return last_insert_id via IPROTO

After this patch client will get last_insert_id
as additional metadata when he executes some
queries.

Part of ...

... document
Title: SQL function last_insert_id.
Function last_insert_id returns first autogenerated ID in
last INSERT/REPLACE statement in current session. Return
value of function is undetermined when more than one
INSERT/REPLACE statements executed asynchronously.
Example:
CREATE TABLE test (id INTEGER PRIMARY KEY AUTOINCREMENT, a INTEGER);
INSERT INTO test VALUES (NULL, 1);
SELECT last_insert_id();

Temporary commit.

TODO:
1) Check that PK != NULL and delete unnesessary 'if' if so.
2) Add tests into gh-2981: insert ... (null, null, null).
3) Review fix.
4) Revert secuence back in case of quety failture.
5) Find out purpose of deleted 'if' in vdbe.c.

src/box/execute.c

@@ -42,6 +42,7 @@
 #include "schema.h"
 #include "port.h"
 #include "tuple.h"
+#include "session.h"
 
 const char *sql_type_strs[] = {
 	NULL,
@@ -640,15 +641,23 @@ sql_response_dump(struct sql_response *response, struct obuf *out)
 		if (iproto_reply_map_key(out, 1, IPROTO_SQL_INFO) != 0)
 			goto err;
 		int changes = sqlite3_changes(db);
+		int64_t last_insert_id = current_session()->sql_last_insert_id;
 		int size = mp_sizeof_uint(SQL_INFO_ROW_COUNT) +
-			   mp_sizeof_uint(changes);
+			   mp_sizeof_uint(changes) +
+			   mp_sizeof_uint(SQL_INFO_LAST_INSERT_ID) +
+			   (last_insert_id >= 0 ?
+			    mp_sizeof_uint(last_insert_id) :
+			    mp_sizeof_int(last_insert_id));
 		char *buf = obuf_alloc(out, size);
 		if (buf == NULL) {
 			diag_set(OutOfMemory, size, "obuf_alloc", "buf");
 			goto err;
 		}
 		buf = mp_encode_uint(buf, SQL_INFO_ROW_COUNT);
 		buf = mp_encode_uint(buf, changes);
+		buf = mp_encode_uint(buf, SQL_INFO_LAST_INSERT_ID);
+		buf = last_insert_id < 0 ? mp_encode_int(buf, last_insert_id) :
+		      mp_encode_uint(buf, last_insert_id);
 	}
 	iproto_reply_sql(out, &header_svp, response->sync, schema_version,
 			 keys);

src/box/execute.h

@@ -42,6 +42,7 @@ extern "C" {
 /** Keys of IPROTO_SQL_INFO map. */
 enum sql_info_key {
 	SQL_INFO_ROW_COUNT = 0,
+	SQL_INFO_LAST_INSERT_ID = 1,
 	sql_info_key_MAX,
 };
 

src/box/lua/net_box.c

@@ -667,16 +667,22 @@ static void
 netbox_decode_sql_info(struct lua_State *L, const char **data)
 {
 	uint32_t map_size = mp_decode_map(data);
-	/* Only SQL_INFO_ROW_COUNT is available. */
 	assert(map_size == 1);
 	(void) map_size;
 	uint32_t key = mp_decode_uint(data);
 	assert(key == SQL_INFO_ROW_COUNT);
-	(void) key;
 	uint32_t row_count = mp_decode_uint(data);
-	lua_createtable(L, 0, 1);
+	key = mp_decode_uint(data);
+	assert(key == SQL_INFO_LAST_INSERT_ID);
+	(void) key;
+	int64_t last_insert_id = mp_typeof(**data) == MP_UINT ?
+				 (int64_t) mp_decode_uint(data) :
+				 mp_decode_int(data);
+	lua_createtable(L, 0, 2);
 	lua_pushinteger(L, row_count);
 	lua_setfield(L, -2, "rowcount");
+	lua_pushinteger(L, last_insert_id);
+	lua_setfield(L, -2, "last_insert_id");
 }
 
 static int

src/box/session.cc

@@ -108,6 +108,7 @@ session_create(enum session_type type)
 	session->type = type;
 	session->sql_flags = default_flags;
 	session->sql_default_engine = SQL_STORAGE_ENGINE_MEMTX;
+	session->sql_last_insert_id = 0;
 
 	/* For on_connect triggers. */
 	credentials_init(&session->credentials, guest_user->auth_token,

src/box/session.h

@@ -92,6 +92,8 @@ union session_meta {
 struct session {
 	/** Session id. */
 	uint64_t id;
+	/** First autogenerated ID in last INSERT/REPLACE query */
+	int64_t sql_last_insert_id;
 	/** SQL Tarantool Default storage engine. */
 	uint8_t sql_default_engine;
 	/** SQL Connection flag for current user session */

src/box/sql/func.c

@@ -38,6 +38,7 @@
 #include "vdbeInt.h"
 #include "version.h"
 #include "coll.h"
+#include "src/box/session.h"
 #include <unicode/ustring.h>
 #include <unicode/ucasemap.h>
 #include <unicode/ucnv.h>
@@ -600,6 +601,22 @@ changes(sqlite3_context * context, int NotUsed, sqlite3_value ** NotUsed2)
 	sqlite3_result_int(context, sqlite3_changes(db));
 }
 
+/*
+ * Implementation of the last_insert_id() function. Returns first
+ * autogenerated ID in last INSERT/REPLACE in current session.
+ *
+ * @param context Context being used.
+ * @param not_used Unused.
+ * @param not_used2 Unused.
+ */
+static void
+last_insert_id(sqlite3_context *context, int not_used,
+	       sqlite3_value **not_used2)
+{
+	UNUSED_PARAMETER2(not_used, not_used2);
+	sqlite3_result_int(context, current_session()->sql_last_insert_id);
+}
+
 /*
  * Implementation of the total_changes() SQL function.  The return value is
  * the same as the sqlite3_total_changes() API function.
@@ -1847,6 +1864,7 @@ sqlite3RegisterBuiltinFunctions(void)
 		FUNCTION(lower, 1, 0, 1, LowerICUFunc),
 		FUNCTION(hex, 1, 0, 0, hexFunc),
 		FUNCTION2(ifnull, 2, 0, 0, noopFunc, SQLITE_FUNC_COALESCE),
+		VFUNCTION(last_insert_id, 0, 0, 0, last_insert_id),
 		VFUNCTION(random, 0, 0, 0, randomFunc),
 		VFUNCTION(randomblob, 1, 0, 0, randomBlob),
 		FUNCTION(nullif, 2, 0, 1, nullifFunc),

src/box/sql/insert.c

@@ -739,9 +739,7 @@ sqlite3Insert(Parse * pParse,	/* Parser context */
 			if (j < 0 || nColumn == 0
 			    || (pColumn && j >= pColumn->nId)) {
 				if (i == pTab->iAutoIncPKey) {
-					sqlite3VdbeAddOp2(v,
-							  OP_NextAutoincValue,
-							  pTab->def->id,
+					sqlite3VdbeAddOp2(v, OP_Null, 0,
 							  iRegStore);
 					continue;
 				}
@@ -824,7 +822,10 @@ sqlite3Insert(Parse * pParse,	/* Parser context */
 						iRegStore);
 			}
 		}
-
+		if (pTab->iAutoIncPKey >= 0) {
+			sqlite3VdbeAddOp2(v, OP_NextAutoincValue, pTab->def->id,
+					  regData + pTab->iAutoIncPKey);
+		}
 		/* Generate code to check constraints and generate index keys
 		   and do the insertion.
 		 */

src/box/sql/vdbe.c

@@ -599,6 +599,11 @@ int sqlite3VdbeExec(Vdbe *p)
 	u64 start;                 /* CPU clock count at start of opcode */
 #endif
 	struct session *user_session = current_session();
+	/*
+	 * Field sql_last_insert_id of current session should be
+	 * set no more than once for each query.
+	 */
+	bool last_insert_id_is_set = false;
 	/*** INSERT STACK UNION HERE ***/
 
 	assert(p->magic==VDBE_MAGIC_RUN);  /* sqlite3_step() verifies this */
@@ -1146,6 +1151,10 @@ case OP_NextAutoincValue: {
 	assert(pOp->p1 > 0);
 	assert(pOp->p2 > 0);
 
+	pOut = &p->aMem[pOp->p2];
+	if ((pOut->flags & MEM_Null) == 0)
+		break;
+
 	struct space *space = space_by_id(pOp->p1);
 	if (space == NULL) {
 		rc = SQL_TARANTOOL_ERROR;
@@ -1163,6 +1172,13 @@ case OP_NextAutoincValue: {
 	pOut->flags = MEM_Int;
 	pOut->u.i = value;
 
+	/* set last_insert_id of session */
+	if (!last_insert_id_is_set) {
+		struct session *session = current_session();
+		session->sql_last_insert_id = value;
+		last_insert_id_is_set = true;
+	}
+
 	break;
 }
 
@@ -3773,7 +3789,7 @@ case OP_FCopy: {     /* out2 */
 
 	if ((pOp->p3 & OPFLAG_NOOP_IF_NULL) && (pIn1->flags & MEM_Null)) {
 		pOut = &aMem[pOp->p2];
-		if (pOut->flags & MEM_Undefined) pOut->flags = MEM_Null;
+		pOut->flags = MEM_Null;
 		/* Flag is set and register is NULL -> do nothing  */
 	} else {
 		assert(memIsValid(pIn1));

test/sql-tap/insert3.test.lua

@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 test = require("sqltester")
-test:plan(18)
+test:plan(20)
 
 --!./tcltestrunner.lua
 -- 2005 January 13
@@ -262,6 +262,31 @@ test:do_execsql_test(
 		-- <insert3-4.1>
 })
 
+-- gh-2618 function last_insert_id
+test:execsql("CREATE TABLE t8(id INTEGER PRIMARY KEY AUTOINCREMENT, a INT);")
+test:do_execsql_test(
+    "insert3-5.1",
+    [[
+        INSERT INTO t8 VALUES (null, 11);
+        SELECT LAST_INSERT_ID();
+    ]], {
+        -- <insert3-5.1>
+        1
+        -- <insert3-5.1>
+})
+
+test:do_execsql_test(
+    "insert3-5.2",
+    [[
+        INSERT INTO t8 VALUES (null, 44), (null, 55), (null, 66);
+        SELECT LAST_INSERT_ID();
+    ]], {
+        -- <insert3-5.1>
+        2
+        -- <insert3-5.1>
+})
+
+
 test:drop_all_tables()
 ---------------------------------------------------------------------------
 -- While developing tests for a different feature (savepoint) the following

test/sql/errinj.result

@@ -73,7 +73,8 @@ while f1:status() ~= 'dead' do fiber.sleep(0) end
 ...
 insert_res
 ---
-- rowcount: 1
+- last_insert_id: 0
+  rowcount: 1
 ...
 select_res
 ---