在mysql的命令提示符下，执行下面一句话,查看mysql服务器的所有全局配置信息：
mysql> show global variables;
得到：
上表的文本内容：
"Variable_name" "Value"
"auto_increment_increment" "1"
"auto_increment_offset" "1"
"autocommit" "ON"
"automatic_sp_privileges" "ON"
"back_log" "50"
"basedir" "C:\\Program Files (x86)\\MySQL\\MySQL Server 5.1\\"
"big_tables" "OFF"
"binlog_cache_size" "32768"
"binlog_direct_non_transactional_updates" "OFF"
"binlog_format" "STATEMENT"
"bulk_insert_buffer_size" "8388608"
"character_set_client" "utf8"
"character_set_connection" "utf8"
"character_set_database" "utf8"
"character_set_filesystem" "binary"
"character_set_results" "utf8"
"character_set_server" "utf8"
"character_set_system" "utf8"
"character_sets_dir" "C:\\Program Files (x86)\\MySQL\\MySQL Server 5.1\\share\\charsets\\"
"collation_connection" "utf8_general_ci"
"collation_database" "utf8_general_ci"
"collation_server" "utf8_general_ci"
"completion_type" "0"
"concurrent_insert" "1"
"connect_timeout" "10"
"datadir" "D:\\ProgramData\\MySQL\\MySQL Server 5.1\\Data\\"
"date_format" "%Y-%m-%d"
"datetime_format" "%Y-%m-%d %H:%i:%s"
"default_week_format" "0"
"delay_key_write" "ON"
"delayed_insert_limit" "100"
"delayed_insert_timeout" "300"
"delayed_queue_size" "1000"
"div_precision_increment" "4"
"engine_condition_pushdown" "ON"
"error_count" "0"
"event_scheduler" "OFF"
"expire_logs_days" "0"
"flush" "OFF"
"flush_time" "1800"
"foreign_key_checks" "ON"
"ft_boolean_syntax" "+ -><()~*:""""&|"
"ft_max_word_len" "84"
"ft_min_word_len" "4"
"ft_query_expansion_limit" "20"
"ft_stopword_file" "(built-in)"
"general_log" "ON"
"general_log_file" "D:\\ProgramData\\MySQL\\MySQL Server 5.1\\Data\\WIN-2736PK059N6.log"
"group_concat_max_len" "102400"
"have_community_features" "YES"
"have_compress" "YES"
"have_crypt" "NO"
"have_csv" "YES"
"have_dynamic_loading" "YES"
"have_geometry" "YES"
"have_innodb" "YES"
"have_ndbcluster" "NO"
"have_openssl" "DISABLED"
"have_partitioning" "YES"
"have_query_cache" "YES"
"have_rtree_keys" "YES"
"have_ssl" "DISABLED"
"have_symlink" "YES"
"hostname" "WIN-2736PK059N6"
"identity" "0"
"ignore_builtin_innodb" "OFF"
"init_connect" "SET NAMES utf8"
"init_file" ""
"init_slave" ""
"innodb_adaptive_hash_index" "ON"
"innodb_additional_mem_pool_size" "8388608"
"innodb_autoextend_increment" "8"
"innodb_autoinc_lock_mode" "1"
"innodb_buffer_pool_size" "378535936"
"innodb_checksums" "ON"
"innodb_commit_concurrency" "0"
"innodb_concurrency_tickets" "500"
"innodb_data_file_path" "ibdata1:10M:autoextend"
"innodb_data_home_dir" ""
"innodb_doublewrite" "ON"
"innodb_fast_shutdown" "1"
"innodb_file_io_threads" "4"
"innodb_file_per_table" "OFF"
"innodb_flush_log_at_trx_commit" "1"
"innodb_flush_method" ""
"innodb_force_recovery" "0"
"innodb_lock_wait_timeout" "50"
"innodb_locks_unsafe_for_binlog" "OFF"
"innodb_log_buffer_size" "4194304"
"innodb_log_file_size" "76546048"
"innodb_log_files_in_group" "2"
"innodb_log_group_home_dir" ".\\"
"innodb_max_dirty_pages_pct" "90"
"innodb_max_purge_lag" "0"
"innodb_mirrored_log_groups" "1"
"innodb_open_files" "300"
"innodb_rollback_on_timeout" "OFF"
"innodb_stats_on_metadata" "ON"
"innodb_support_xa" "ON"
"innodb_sync_spin_loops" "20"
"innodb_table_locks" "ON"
"innodb_thread_concurrency" "8"
"innodb_thread_sleep_delay" "10000"
"innodb_use_legacy_cardinality_algorithm" "ON"
"insert_id" "0"
"interactive_timeout" "288000"
"join_buffer_size" "131072"
"keep_files_on_create" "OFF"
"key_buffer_size" "195035136"
"key_cache_age_threshold" "300"
"key_cache_block_size" "1024"
"key_cache_division_limit" "100"
"language" "C:\\Program Files (x86)\\MySQL\\MySQL Server 5.1\\share\\english\\"
"large_files_support" "ON"
"large_page_size" "0"
"large_pages" "OFF"
"last_insert_id" "0"
"lc_time_names" "en_US"
"license" "GPL"
"local_infile" "ON"
"log" "ON"
"log_bin" "OFF"
"log_bin_trust_function_creators" "OFF"
"log_bin_trust_routine_creators" "OFF"
"log_error" "D:\\ProgramData\\MySQL\\MySQL Server 5.1\\Data\\WIN-2736PK059N6.err"
"log_output" "FILE"
"log_queries_not_using_indexes" "OFF"
"log_slave_updates" "OFF"
"log_slow_queries" "ON"
"log_warnings" "1"
"long_query_time" "3.000000"
"low_priority_updates" "OFF"
"lower_case_file_system" "ON"
"lower_case_table_names" "1"
"max_allowed_packet" "524288000"
"max_binlog_cache_size" "4294963200"
"max_binlog_size" "1073741824"
"max_connect_errors" "10"
"max_connections" "1510"
"max_delayed_threads" "20"
"max_error_count" "64"
"max_heap_table_size" "16777216"
"max_insert_delayed_threads" "20"
"max_join_size" "18446744073709551615"
"max_length_for_sort_data" "1024"
"max_prepared_stmt_count" "16382"
"max_relay_log_size" "0"
"max_seeks_for_key" "4294967295"
"max_sort_length" "1024"
"max_sp_recursion_depth" "0"
"max_tmp_tables" "32"
"max_user_connections" "0"
"max_write_lock_count" "4294967295"
"min_examined_row_limit" "0"
"multi_range_count" "256"
"myisam_data_pointer_size" "6"
"myisam_max_sort_file_size" "107374182400"
"myisam_mmap_size" "4294967295"
"myisam_recover_options" "OFF"
"myisam_repair_threads" "1"
"myisam_sort_buffer_size" "23068672"
"myisam_stats_method" "nulls_unequal"
"myisam_use_mmap" "OFF"
"named_pipe" "OFF"
"net_buffer_length" "16384"
"net_read_timeout" "30"
"net_retry_count" "10"
"net_write_timeout" "60"
"new" "OFF"
"old" "OFF"
"old_alter_table" "OFF"
"old_passwords" "OFF"
"open_files_limit" "2048"
"optimizer_prune_level" "1"
"optimizer_search_depth" "62"
"optimizer_switch" "index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on"
"pid_file" "D:\\ProgramData\\MySQL\\MySQL Server 5.1\\Data\\WIN-2736PK059N6.pid"
"plugin_dir" "C:\\Program Files (x86)\\MySQL\\MySQL Server 5.1\\lib/plugin"
"port" "3306"
"preload_buffer_size" "32768"
"profiling" "OFF"
"profiling_history_size" "15"
"protocol_version" "10"
"pseudo_thread_id" "0"
"query_alloc_block_size" "8192"
"query_cache_limit" "1048576"
"query_cache_min_res_unit" "4096"
"query_cache_size" "127926272"
"query_cache_type" "ON"
"query_cache_wlock_invalidate" "OFF"
"query_prealloc_size" "8192"
"rand_seed1" ""
"rand_seed2" ""
"range_alloc_block_size" "4096"
"read_buffer_size" "65536"
"read_only" "OFF"
"read_rnd_buffer_size" "262144"
"relay_log" ""
"relay_log_index" ""
"relay_log_info_file" "relay-log.info"
"relay_log_purge" "ON"
"relay_log_space_limit" "0"
"report_host" ""
"report_password" ""
"report_port" "3306"
"report_user" ""
"rpl_recovery_rank" "0"
"secure_auth" "OFF"
"secure_file_priv" ""
"server_id" "0"
"shared_memory" "OFF"
"shared_memory_base_name" "MYSQL"
"skip_external_locking" "ON"
"skip_name_resolve" "ON"
"skip_networking" "OFF"
"skip_show_database" "OFF"
"slave_compressed_protocol" "OFF"
"slave_exec_mode" "STRICT"
"slave_load_tmpdir" "C:\\Windows\\TEMP"
"slave_net_timeout" "3600"
"slave_skip_errors" "OFF"
"slave_transaction_retries" "10"
"slow_launch_time" "2"
"slow_query_log" "ON"
"slow_query_log_file" "C:\\Program Files (x86)\\MySQL\\MySQL Server 5.1\\mysqllog/slowquery.log"
"socket" "MySQL"
"sort_buffer_size" "262144"
"sql_auto_is_null" "ON"
"sql_big_selects" "ON"
"sql_big_tables" "OFF"
"sql_buffer_result" "OFF"
"sql_log_bin" "ON"
"sql_log_off" "OFF"
"sql_log_update" "ON"
"sql_low_priority_updates" "OFF"
"sql_max_join_size" "18446744073709551615"
"sql_mode" "STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
"sql_notes" "ON"
"sql_quote_show_create" "ON"
"sql_safe_updates" "OFF"
"sql_select_limit" "18446744073709551615"
"sql_slave_skip_counter" ""
"sql_warnings" "OFF"
"ssl_ca" ""
"ssl_capath" ""
"ssl_cert" ""
"ssl_cipher" ""
"ssl_key" ""
"storage_engine" "InnoDB"
"sync_binlog" "0"
"sync_frm" "ON"
"system_time_zone" ""
"table_definition_cache" "256"
"table_lock_wait_timeout" "50"
"table_open_cache" "264"
"table_type" "InnoDB"
"thread_cache_size" "64"
"thread_handling" "one-thread-per-connection"
"thread_stack" "196608"
"time_format" "%H:%i:%s"
"time_zone" "SYSTEM"
"timed_mutexes" "OFF"
"timestamp" "1484874972"
"tmp_table_size" "23068672"
"tmpdir" "C:\\Windows\\TEMP"
"transaction_alloc_block_size" "8192"
"transaction_prealloc_size" "4096"
"tx_isolation" "REPEATABLE-READ"
"unique_checks" "ON"
"updatable_views_with_limit" "YES"
"version" "5.1.53-community-log"
"version_comment" "MySQL Community Server (GPL)"
"version_compile_machine" "ia32"
"version_compile_os" "Win32"
"wait_timeout" "288000"
"warning_count" "1"
如果需要在众多的全局变量中，找到某一个变量的值的办法是在上边的命令后面使用 “LIKE %需要的特征值%”模糊查找包含特征值的全局配置。
例如：
1.mysql查看数据库的数据存放目录命令：
>mysql> show global variables like "%datadir%";
