td-909: add verification for some API

tests/examples/c/apitest.c

+// sample code to verify all TDengine API
+// to compile: gcc -o apitest apitest.c -ltaos
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <taos.h>
+#include <unistd.h>
+
+
+static void prepare_data(TAOS* taos) {
+  taos_query(taos, "drop database if exists test;");
+  usleep(100000);
+  taos_query(taos, "create database test;");
+  usleep(100000);
+  taos_select_db(taos, "test");
+
+  taos_query(taos, "create table meters(ts timestamp, a int) tags(area int);");
+
+  taos_query(taos, "create table t0 using meters tags(0);");
+  taos_query(taos, "create table t1 using meters tags(1);");
+  taos_query(taos, "create table t2 using meters tags(2);");
+  taos_query(taos, "create table t3 using meters tags(3);");
+  taos_query(taos, "create table t4 using meters tags(4);");
+  taos_query(taos, "create table t5 using meters tags(5);");
+  taos_query(taos, "create table t6 using meters tags(6);");
+  taos_query(taos, "create table t7 using meters tags(7);");
+  taos_query(taos, "create table t8 using meters tags(8);");
+  taos_query(taos, "create table t9 using meters tags(9);");
+
+  TAOS_RES* res = taos_query(taos, "insert into t0 values('2020-01-01 00:00:00.000', 0)"
+    " ('2020-01-01 00:01:00.000', 0)"
+    " ('2020-01-01 00:02:00.000', 0)"
+    " t1 values('2020-01-01 00:00:00.000', 0)"
+    " ('2020-01-01 00:01:00.000', 0)"
+    " ('2020-01-01 00:02:00.000', 0)"
+    " ('2020-01-01 00:03:00.000', 0)"
+    " t2 values('2020-01-01 00:00:00.000', 0)"
+    " ('2020-01-01 00:01:00.000', 0)"
+    " ('2020-01-01 00:01:01.000', 0)"
+    " ('2020-01-01 00:01:02.000', 0)"
+    " t3 values('2020-01-01 00:01:02.000', 0)"
+    " t4 values('2020-01-01 00:01:02.000', 0)"
+    " t5 values('2020-01-01 00:01:02.000', 0)"
+    " t6 values('2020-01-01 00:01:02.000', 0)"
+    " t7 values('2020-01-01 00:01:02.000', 0)"
+    " t8 values('2020-01-01 00:01:02.000', 0)"
+    " t9 values('2020-01-01 00:01:02.000', 0)");
+  int affected = taos_affected_rows(res);
+  if (affected != 18) {
+    printf("\033[31m%d rows affected by last insert statement, but it should be 18\033[0m\n", affected);
+  }
+  // super tables subscription
+  usleep(1000000);
+}
+
+
+static int print_result(TAOS_RES* res, int blockFetch) {
+  TAOS_ROW    row = NULL;
+  int         num_fields = taos_num_fields(res);
+  TAOS_FIELD* fields = taos_fetch_fields(res);
+  int         nRows = 0;
+
+  if (blockFetch) {
+    int rows = 0;
+    while ((rows = taos_fetch_block(res, &row))) {
+      for (int i = 0; i < rows; i++) {
+        char temp[256];
+        taos_print_row(temp, row + i, fields, num_fields);
+        puts(temp);
+      }
+      nRows += rows;
+    }
+  } else {
+    while ((row = taos_fetch_row(res))) {
+      char temp[256];
+      taos_print_row(temp, row, fields, num_fields);
+      puts(temp);
+      nRows++;
+    }
+  }
+
+  printf("%d rows consumed.\n", nRows);
+  return nRows;
+}
+
+
+static void check_row_count(int line, TAOS_RES* res, int expected) {
+  int actual = print_result(res, expected % 2);
+  if (actual != expected) {
+    printf("\033[31mline %d: row count mismatch, expected: %d, actual: %d\033[0m\n", line, expected, actual);
+  } else {
+    printf("line %d: %d rows consumed as expected\n", line, actual);
+  }
+}
+
+
+static void verify_query(TAOS* taos) {
+  prepare_data(taos);
+
+  int code = taos_validate_sql(taos, "select * from nonexisttable");
+  if (code == 0) {
+    printf("\033[31mimpossible, the table does not exists\033[0m\n");
+  }
+
+  code = taos_validate_sql(taos, "select * from meters");
+  if (code != 0) {
+    printf("\033[31mimpossible, the table does exists: 0x%08x\033[0m\n", code);
+  }
+
+  TAOS_RES* res = taos_query(taos, "select * from meters");
+  check_row_count(__LINE__, res, 18);
+  printf("result precision is: %d\n",  taos_result_precision(res));
+  int c = taos_field_count(res);
+  printf("field count is: %d\n",  c);
+  int* lengths = taos_fetch_lengths(res);
+  for (int i = 0; i < c; i++) {
+    printf("length of column %d is %d\n", i, lengths[i]);
+  }
+  taos_free_result(res);
+
+  res = taos_query(taos, "select * from t0");
+  check_row_count(__LINE__, res, 3);
+  taos_free_result(res);
+
+  res = taos_query(taos, "select * from nonexisttable");
+  code = taos_errno(res);
+  printf("code=%d, error msg=%s\n", code, taos_errstr(res));
+  taos_free_result(res);
+}
+
+
+static void verify_subscribe(TAOS* taos) {
+  prepare_data(taos);
+
+  TAOS_SUB* tsub = taos_subscribe(taos, 0, "test", "select * from meters;", NULL, NULL, 0);
+  TAOS_RES* res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 18);
+
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 0);
+
+  taos_query(taos, "insert into t0 values('2020-01-01 00:02:00.001', 0);");
+  taos_query(taos, "insert into t8 values('2020-01-01 00:01:03.000', 0);");
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 2);
+
+  taos_query(taos, "insert into t2 values('2020-01-01 00:01:02.001', 0);");
+  taos_query(taos, "insert into t1 values('2020-01-01 00:03:00.001', 0);");
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 2);
+
+  taos_query(taos, "insert into t1 values('2020-01-01 00:03:00.002', 0);");
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 1);
+
+  // keep progress information and restart subscription
+  taos_unsubscribe(tsub, 1);
+  taos_query(taos, "insert into t0 values('2020-01-01 00:04:00.000', 0);");
+  tsub = taos_subscribe(taos, 1, "test", "select * from meters;", NULL, NULL, 0);
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 24);
+
+  // keep progress information and continue previous subscription
+  taos_unsubscribe(tsub, 1);
+  tsub = taos_subscribe(taos, 0, "test", "select * from meters;", NULL, NULL, 0);
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 0);
+
+  // don't keep progress information and continue previous subscription
+  taos_unsubscribe(tsub, 0);
+  tsub = taos_subscribe(taos, 0, "test", "select * from meters;", NULL, NULL, 0);
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 24);
+
+  // single meter subscription
+
+  taos_unsubscribe(tsub, 0);
+  tsub = taos_subscribe(taos, 0, "test", "select * from t0;", NULL, NULL, 0);
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 5);
+
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 0);
+
+  taos_query(taos, "insert into t0 values('2020-01-01 00:04:00.001', 0);");
+  res = taos_consume(tsub);
+  check_row_count(__LINE__, res, 1);
+
+  taos_unsubscribe(tsub, 0);
+}
+
+
+void verify_prepare(TAOS* taos) {
+  TAOS_RES* result = taos_query(taos, "drop database if exists test;");
+  usleep(100000);
+  taos_query(taos, "create database test;");
+
+  int code = taos_errno(result);
+  if (code != 0) {
+    printf("failed to create database, reason:%s\n", taos_errstr(result));
+    taos_free_result(result);
+    exit(1);
+  }
+  taos_free_result(result);
+
+  usleep(100000);
+  taos_select_db(taos, "test");
+
+  // create table
+  const char* sql = "create table m1 (ts timestamp, b bool, v1 tinyint, v2 smallint, v4 int, v8 bigint, f4 float, f8 double, bin binary(40), blob nchar(10))";
+  result = taos_query(taos, sql);
+  code = taos_errno(result);
+  if (code != 0) {
+    printf("failed to create table, reason:%s\n", taos_errstr(result));
+    taos_free_result(result);
+    exit(1);
+  }
+  taos_free_result(result);
+
+  // insert 10 records
+  struct {
+      int64_t ts;
+      int8_t b;
+      int8_t v1;
+      int16_t v2;
+      int32_t v4;
+      int64_t v8;
+      float f4;
+      double f8;
+      char bin[40];
+      char blob[80];
+  } v = {0};
+
+  TAOS_STMT* stmt = taos_stmt_init(taos);
+  TAOS_BIND params[10];
+  params[0].buffer_type = TSDB_DATA_TYPE_TIMESTAMP;
+  params[0].buffer_length = sizeof(v.ts);
+  params[0].buffer = &v.ts;
+  params[0].length = &params[0].buffer_length;
+  params[0].is_null = NULL;
+
+  params[1].buffer_type = TSDB_DATA_TYPE_BOOL;
+  params[1].buffer_length = sizeof(v.b);
+  params[1].buffer = &v.b;
+  params[1].length = &params[1].buffer_length;
+  params[1].is_null = NULL;
+
+  params[2].buffer_type = TSDB_DATA_TYPE_TINYINT;
+  params[2].buffer_length = sizeof(v.v1);
+  params[2].buffer = &v.v1;
+  params[2].length = &params[2].buffer_length;
+  params[2].is_null = NULL;
+
+  params[3].buffer_type = TSDB_DATA_TYPE_SMALLINT;
+  params[3].buffer_length = sizeof(v.v2);
+  params[3].buffer = &v.v2;
+  params[3].length = &params[3].buffer_length;
+  params[3].is_null = NULL;
+
+  params[4].buffer_type = TSDB_DATA_TYPE_INT;
+  params[4].buffer_length = sizeof(v.v4);
+  params[4].buffer = &v.v4;
+  params[4].length = &params[4].buffer_length;
+  params[4].is_null = NULL;
+
+  params[5].buffer_type = TSDB_DATA_TYPE_BIGINT;
+  params[5].buffer_length = sizeof(v.v8);
+  params[5].buffer = &v.v8;
+  params[5].length = &params[5].buffer_length;
+  params[5].is_null = NULL;
+
+  params[6].buffer_type = TSDB_DATA_TYPE_FLOAT;
+  params[6].buffer_length = sizeof(v.f4);
+  params[6].buffer = &v.f4;
+  params[6].length = &params[6].buffer_length;
+  params[6].is_null = NULL;
+
+  params[7].buffer_type = TSDB_DATA_TYPE_DOUBLE;
+  params[7].buffer_length = sizeof(v.f8);
+  params[7].buffer = &v.f8;
+  params[7].length = &params[7].buffer_length;
+  params[7].is_null = NULL;
+
+  params[8].buffer_type = TSDB_DATA_TYPE_BINARY;
+  params[8].buffer_length = sizeof(v.bin);
+  params[8].buffer = v.bin;
+  params[8].length = &params[8].buffer_length;
+  params[8].is_null = NULL;
+
+  strcpy(v.blob, "一二三四五六七八九十");
+  params[9].buffer_type = TSDB_DATA_TYPE_NCHAR;
+  params[9].buffer_length = strlen(v.blob);
+  params[9].buffer = v.blob;
+  params[9].length = &params[9].buffer_length;
+  params[9].is_null = NULL;
+
+  int is_null = 1;
+
+  sql = "insert into m1 values(?,?,?,?,?,?,?,?,?,?)";
+  code = taos_stmt_prepare(stmt, sql, 0);
+  if (code != 0){
+    printf("failed to execute taos_stmt_prepare. code:0x%x\n", code);
+  }
+  v.ts = 1591060628000;
+  for (int i = 0; i < 10; ++i) {
+    v.ts += 1;
+    for (int j = 1; j < 10; ++j) {
+      params[j].is_null = ((i == j) ? &is_null : 0);
+    }
+    v.b = (int8_t)i % 2;
+    v.v1 = (int8_t)i;
+    v.v2 = (int16_t)(i * 2);
+    v.v4 = (int32_t)(i * 4);
+    v.v8 = (int64_t)(i * 8);
+    v.f4 = (float)(i * 40);
+    v.f8 = (double)(i * 80);
+    for (int j = 0; j < sizeof(v.bin) - 1; ++j) {
+      v.bin[j] = (char)(i + '0');
+    }
+
+    taos_stmt_bind_param(stmt, params);
+    taos_stmt_add_batch(stmt);
+  }
+  if (taos_stmt_execute(stmt) != 0) {
+    printf("failed to execute insert statement.\n");
+    exit(1);
+  }
+  taos_stmt_close(stmt);
+
+  // query the records
+  stmt = taos_stmt_init(taos);
+  taos_stmt_prepare(stmt, "SELECT * FROM m1 WHERE v1 > ? AND v2 < ?", 0);
+  v.v1 = 5;
+  v.v2 = 15;
+  taos_stmt_bind_param(stmt, params + 2);
+  if (taos_stmt_execute(stmt) != 0) {
+    printf("failed to execute select statement.\n");
+    exit(1);
+  }
+
+  result = taos_stmt_use_result(stmt);
+
+  TAOS_ROW    row;
+  int         rows = 0;
+  int         num_fields = taos_num_fields(result);
+  TAOS_FIELD *fields = taos_fetch_fields(result);
+  char        temp[256];
+
+  // fetch the records row by row
+  while ((row = taos_fetch_row(result))) {
+    rows++;
+    taos_print_row(temp, row, fields, num_fields);
+    printf("%s\n", temp);
+  }
+
+  taos_free_result(result);
+  taos_stmt_close(stmt);
+}
+
+void verify_stream(TAOS* taos) {
+}
+
+int main(int argc, char *argv[]) {
+  const char* host = "127.0.0.1";
+  const char* user = "root";
+  const char* passwd = "taosdata";
+
+  taos_options(TSDB_OPTION_TIMEZONE, "GMT-8");
+  taos_init();
+
+  TAOS* taos = taos_connect(host, user, passwd, "", 0);
+  if (taos == NULL) {
+    printf("failed to connect to db, reason:%s\n", taos_errstr(taos));
+    exit(1);
+  }
+
+  char* info = taos_get_server_info(taos);
+  printf("server info: %s\n", info);
+  info = taos_get_client_info(taos);
+  printf("client info: %s\n", info);
+
+  printf("************  verify query  *************\n");
+  verify_query(taos);
+  printf("*********** verify subscribe ************\n");
+  verify_subscribe(taos);
+  printf("************ verify prepare *************\n");
+  verify_prepare(taos);
+  printf("************ verify stream  *************\n");
+  verify_stream(taos);
+
+  taos_close(taos);
+  taos_cleanup();
+}
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