Difference between revisions of "AMI SQL"
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The resulting table will be called <span style="color: blue;">TABLE</span> and contain two String columns: <span style="color: blue;">TableName</span> and <span style="color: blue;">Schema</span> | The resulting table will be called <span style="color: blue;">TABLE</span> and contain two String columns: <span style="color: blue;">TableName</span> and <span style="color: blue;">Schema</span> | ||
− | '''Syntax''' | + | '''Syntax''' <syntaxhighlight lang="amiscript"> |
+ | USE ds="mydb" SHOW TABLES; | ||
+ | </syntaxhighlight>'''Example''' | ||
− | + | This example will return a table displaying all tables available in the ''mydb'' datasource. If the datasource supports schema names, that will be populated as well. | |
− | + | <span style="font-family: courier new; color: blue;">USE ds="mydb" SHOW TABLES;</span> | |
− | + | <span style="font-family: courier new; color: blue;">//returns:</span> | |
− | |||
− |
Revision as of 14:09, 19 March 2021
Goals
The 3Forge SQL language provides a comprehensive instruction set for working with table(s) of data.
- Retrieval - Accessing and Normalizing data from external sources
- Blending - Perform Joins and Unions on tables
- Modifying - Inserting, Updating, and Deleting rows
- Analyzing - Grouping, Sorting, and Filtering
- Schema Definition - Creating, Updating, and Dropping tables
Broadly speaking, the logic steps involved in data-visualization are:
1. Running a query, or set of queries, on external datasources and/or the AMI-Realtime database.
- Each datasource is predefined and uniquely named.
- The results of queries on datasources will result in temporary, in-memory tables
- The queries can be constructed using user-input/user-selected/user-associated data
- In more advanced cases, the queries can be sequential, meaning the results from one query are then fed into a subsequent query (allowing for reactionary data blending)
2. Blending the results from Step 1, resulting in new temporary in-memory tables 3. Building visualizations on the tables from Step 1 and/or Step 2
AMI SQL and Standard SQL Differences
For those familiar with standard SQL, these are the differences:
1. Equality is done with ==
- AMISQL: SELECT * FROM Users WHERE userid == 15;
- MYSQL: SELECT * FROM Users WHERE userid = 15;
2. Checking for null is done with equality, ex. == null
- AMISQL: SELECT * FROM Users WHERE status == null;
- MYSQL: SELECT * FROM Users WHERE status IS NULL;
3. Strings are surrounded in double quotes
- AMISQL: SELECT * FROM Users WHERE name == "David";
- MYSQL: SELECT * FROM Users WHERE name = "David";
4. "Matches" (~~) instead of LIKE
- AMISQL: SELECT * FROM Users WHERE name ~~ "^Dav";
- MYSQL: SELECT * FROM Users WHERE name LIKE "Dav%";
(See Simplified Text Matching for pattern matching rules/expressions)
5. Boolean expressions && works same as AND. || works same as OR
- AMISQL: SELECT * FROM Users WHERE userid == 15 AND status == null && name == "David";
- MYSQL: SELECT * FROM Users WHERE userid = 15 AND status IS NULL && name = "David";
6. By default all tables are TEMPORARY, use the PUBLIC key word to make non-temporary tables:
- AMISQL: CREATE TABLE MyTemporaryTable(id String);
- AMISQL: CREATE PUBLIC TABLE MyPermanantTable(id String);
Data Source Access Clauses
use...execute_clause
Overview
This command enables you to "execute" code on an external datasource and process/store the results locally
- USE: While datamodels have default options, you can override them for a particular query. Valid options include
- ds = "datasource_name"
- The name of the datasource to execute this script on
- timeout = timeout_in_millis
- The number of milliseconds before the execute command times out
- limit = row_limit_to_return
- The max number of records returned
- ds_url = "url"
- Overrides the url of the datasource
- When used in conjunction with ds="datasource_name", supplied datasource must contain URL in the PermittedOverrides field
- ds_username = "username"
- Overrides the username of the datasource
- When used in conjunction with ds="datasource_name", supplied datasource must contain USERNAME in the PermittedOverrides field
- ds_password = "plain_text_password"
- Overrides the password of the datasource using a plain text password
- When used in conjunction with ds="datasource_name", supplied datasource must contain PASSWORD in the PermittedOverrides field
- Mutually exclusive with the ds_password_enc option
- ds_password_enc = "aes_encrypted_password"
- Overrides the password of the datasource, using an encrypted password
- Use strEncrypt(...) to create an encrypted password
- When used in conjunction with ds="datasource_name", supplied datasource must contain PASSWORD in the PermittedOverrides field
- Mutually exclusive with the ds_password option
- ds_options = "some options"
- Override the options of the datasource
- When used in conjunction with ds="datasource_name", supplied datasource must contain OPTIONS in the PermittedOverrides field
- ds_relay = "relayid"
- Override the relay of the datasource
- Run SHOW RELAYS command and inspect RelayId for available relays
- When used in conjunction with ds="datasource_name", supplied datasource must contain RELAY in the PermittedOverrides field
- ds_adapter = "SOME_ADAPTER"
- Use an "anonymous" datasource of the specified adapter type
- Run SHOW DATASOURCE_TYPES command and inspect the I column for available adapters
- Mutually exclusive with ds="datasource_name" option
- See ami.db.anonymous.datasources.enabled option for permission details
- _custom=some_directive
- Prefixing with an underbar (_) passes the option through to the datasource's adapter
- ds = "datasource_name"
- EXECUTE: The literal text to execute. The text will be sent directly to the datasource for execution. Therefore, variables cannot be referenced. Instead, substitution can be used. See dollarsign_substitution
Syntax
[USE option = value [ option = value ...]] EXECUTE code_to_execute
Example
CREATE TABLE
final_table AS
USE
ds="mydb"
timeout=10000
limit=100
EXECUTE
select * from mytable;
use ... show tables clause
Overview
This command enables you to see what tables are available on a given datasource (similar to what the AMI gui wizard shows you when selecting a table).
- USE: While datamodels have default options, you can override them for a particular query. Valid options include
- ds = "datasource_name" The name of the datasource to execute ths script on
The resulting table will be called TABLE and contain two String columns: TableName and Schema
Syntax
USE ds="mydb" SHOW TABLES;
Example
This example will return a table displaying all tables available in the mydb datasource. If the datasource supports schema names, that will be populated as well.
USE ds="mydb" SHOW TABLES;
//returns: