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%";
