SQL and Query Processing

interface TableEnvironment {
    TableResult executeSql(String statement);
    Table sqlQuery(String query);
    StatementSet createStatementSet();
}

// Execute DDL statements
tEnv.executeSql("CREATE DATABASE mydb");
tEnv.executeSql("USE mydb");

// Execute DML statements  
TableResult result = tEnv.executeSql("INSERT INTO target_table SELECT * FROM source_table");

// Execute queries
Table queryResult = tEnv.sqlQuery("SELECT user_id, COUNT(*) as cnt FROM clicks GROUP BY user_id");

-- Create database
CREATE DATABASE [IF NOT EXISTS] db_name [COMMENT 'comment'] [WITH (key1=val1, key2=val2, ...)];

-- Drop database
DROP DATABASE [IF EXISTS] db_name [RESTRICT|CASCADE];

-- Show databases
SHOW DATABASES;

-- Use database
USE db_name;

-- Create table
CREATE TABLE [IF NOT EXISTS] table_name (
    column_name column_type [COMMENT 'comment'],
    [WATERMARK FOR rowtime_column AS watermark_strategy],
    [PRIMARY KEY (column_list) NOT ENFORCED]
) [COMMENT 'comment']
[PARTITIONED BY (partition_column_list)]
WITH (
    'connector' = 'connector_type',
    'option_key' = 'option_value'
);

-- Create table as select
CREATE TABLE table_name WITH ('connector' = '...') AS SELECT ...;

-- Drop table
DROP TABLE [IF EXISTS] table_name;

-- Show tables
SHOW TABLES;

-- Describe table
DESCRIBE table_name;
DESC table_name;

// Create table with watermark
tEnv.executeSql(
    "CREATE TABLE events (" +
    "  user_id BIGINT," +
    "  event_time TIMESTAMP(3)," +
    "  event_type STRING," +
    "  WATERMARK FOR event_time AS event_time - INTERVAL '5' SECOND" +
    ") WITH (" +
    "  'connector' = 'kafka'," +
    "  'topic' = 'events'," +
    "  'properties.bootstrap.servers' = 'localhost:9092'," +
    "  'format' = 'json'" +
    ")"
);

interface TableEnvironment {
    void createTemporaryView(String path, Table view);
    void createTemporaryView(String path, DataStream<?> dataStream);
    void dropTemporaryView(String path);
}

-- Create view
CREATE [TEMPORARY] VIEW view_name AS SELECT ...;

-- Drop view
DROP [TEMPORARY] VIEW [IF EXISTS] view_name;

-- Show views
SHOW VIEWS;

-- Insert values
INSERT INTO table_name VALUES (value1, value2, ...);

-- Insert from select
INSERT INTO target_table SELECT * FROM source_table WHERE condition;

-- Insert overwrite
INSERT OVERWRITE target_table SELECT * FROM source_table;

-- Update (only supported for changelog streams)
UPDATE table_name SET column1 = value1 WHERE condition;

-- Delete (only supported for changelog streams)  
DELETE FROM table_name WHERE condition;

SELECT column_list
FROM table_name
[WHERE condition]
[GROUP BY column_list]
[HAVING condition]
[ORDER BY column_list]
[LIMIT number];

-- Inner join
SELECT * FROM table1 t1 JOIN table2 t2 ON t1.id = t2.id;

-- Outer joins
SELECT * FROM table1 t1 LEFT JOIN table2 t2 ON t1.id = t2.id;
SELECT * FROM table1 t1 RIGHT JOIN table2 t2 ON t1.id = t2.id;
SELECT * FROM table1 t1 FULL OUTER JOIN table2 t2 ON t1.id = t2.id;

-- Cross join
SELECT * FROM table1 CROSS JOIN table2;

SELECT 
    TUMBLE_START(event_time, INTERVAL '1' HOUR) as window_start,
    TUMBLE_END(event_time, INTERVAL '1' HOUR) as window_end,
    user_id,
    COUNT(*) as event_count
FROM events
GROUP BY TUMBLE(event_time, INTERVAL '1' HOUR), user_id;

SELECT 
    HOP_START(event_time, INTERVAL '30' MINUTE, INTERVAL '1' HOUR) as window_start,
    HOP_END(event_time, INTERVAL '30' MINUTE, INTERVAL '1' HOUR) as window_end,
    COUNT(*) as event_count
FROM events  
GROUP BY HOP(event_time, INTERVAL '30' MINUTE, INTERVAL '1' HOUR);

SELECT 
    SESSION_START(event_time, INTERVAL '30' MINUTE) as session_start,
    SESSION_END(event_time, INTERVAL '30' MINUTE) as session_end,
    user_id,
    COUNT(*) as event_count
FROM events
GROUP BY SESSION(event_time, INTERVAL '30' MINUTE), user_id;

interface TableEnvironment {
    SqlParser createParser(String statement);
}

class SqlParser {
    List<SqlNode> parseStmtList(String sql);
    SqlNode parseStmt(String sql);
    SqlNode parseExpression(String sqlExpression);
}

enum SqlDialect {
    DEFAULT,
    HIVE
}

// Set SQL dialect
Configuration config = new Configuration();
config.setString("table.sql-dialect", "hive");
TableEnvironment tEnv = TableEnvironment.create(config);

// Or via table config
tEnv.getConfig().getConfiguration().setString("table.sql-dialect", "hive");

-- Hive-style CTAS with storage format
CREATE TABLE target_table
STORED AS PARQUET
LOCATION '/path/to/table'
AS SELECT * FROM source_table;

-- Hive functions
SELECT concat_ws('|', col1, col2) FROM table1;
SELECT get_json_object(json_col, '$.field') FROM table2;

// Register Hive catalog
HiveCatalog hive = new HiveCatalog("myhive", "default", "/path/to/hive-conf");
tEnv.registerCatalog("myhive", hive);
tEnv.useCatalog("myhive");

// Access Hive tables
Table hiveTable = tEnv.from("hive_database.hive_table");

-- String functions
SELECT UPPER(name), LOWER(email), LENGTH(description) FROM users;
SELECT CONCAT(first_name, ' ', last_name) as full_name FROM users;
SELECT SUBSTRING(text, 1, 10) FROM documents;

-- Math functions
SELECT ABS(balance), ROUND(price, 2), CEIL(rating) FROM products;

-- Date/Time functions
SELECT CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP;
SELECT EXTRACT(YEAR FROM order_date), DATE_FORMAT(created_at, 'yyyy-MM-dd') FROM orders;

-- Conditional functions
SELECT CASE WHEN age >= 18 THEN 'adult' ELSE 'minor' END FROM users;
SELECT COALESCE(nickname, first_name, 'Anonymous') FROM users;

-- Basic aggregates
SELECT COUNT(*), SUM(amount), AVG(rating), MIN(price), MAX(price) FROM products;

-- Statistical functions
SELECT STDDEV_POP(score), VAR_SAMP(rating) FROM reviews;

-- Collection functions
SELECT COLLECT(tags), LISTAGG(name, ',') FROM items GROUP BY category;

-- String split
SELECT word FROM table1 CROSS JOIN UNNEST(SPLIT(description, ' ')) AS t(word);

-- JSON extraction
SELECT field_value FROM json_table CROSS JOIN UNNEST(JSON_EXTRACT_ARRAY(json_col)) AS t(field_value);

class SqlParserException extends TableException {
    SqlParserException(String message);
    SqlParserException(String message, Throwable cause);
}

class SqlExecutionException extends TableException;
class SqlValidationException extends ValidationException;

class TableConfigOptions {
    public static final ConfigOption<String> TABLE_SQL_DIALECT;
    public static final ConfigOption<Duration> TABLE_EXEC_RESOURCE_DEFAULT_PARALLELISM;
    public static final ConfigOption<String> TABLE_LOCAL_TIME_ZONE;
}

Configuration config = tEnv.getConfig().getConfiguration();

// Set SQL dialect
config.setString("table.sql-dialect", "default");

// Set local timezone
config.setString("table.local-time-zone", "UTC");

// Set default parallelism
config.setInteger("table.exec.resource.default-parallelism", 4);

interface StatementSet {
    StatementSet addInsertSql(String statement);
    StatementSet addInsert(String targetPath, Table table);
    StatementSet addInsert(String targetPath, Table table, boolean overwrite);
    TableResult execute();
    String explain();
}

StatementSet stmtSet = tEnv.createStatementSet();
stmtSet.addInsertSql("INSERT INTO sink1 SELECT * FROM source WHERE type = 'A'");
stmtSet.addInsertSql("INSERT INTO sink2 SELECT * FROM source WHERE type = 'B'");
stmtSet.execute();

interface TableResult {
    ResultKind getResultKind();
    ResolvedSchema getResolvedSchema();
    CloseableIterator<Row> collect();
    void print();
    JobExecutionResult getJobExecutionResult();
}

enum ResultKind {
    SUCCESS,
    SUCCESS_WITH_CONTENT,
    NOT_READY
}

interface SqlNode;
interface SqlIdentifier extends SqlNode;
interface SqlCall extends SqlNode;