| name | read-strategy |
| description | Strategy for reading data from CAS or SAS tables. Determines which read tool to use (raw reads vs analytical queries).
|
Read Table Strategy
Mandatory two-step sequence — never skip or reorder
Step 1 and Step 2 are required for every read request. Step 2 must never run before Step 1 succeeds.
Step 1 — Verify the table exists and resolve its server (REQUIRED)
GATE:
Do not check for the existence of the library separately. Follow the workflow below. The sas-score-find-table tool will check for the existence of the table in the specified library and server, which implicitly verifies the library as well.
Workflow to read a table
Step 1 — Verify the table exists and resolve its server (REQUIRED)
- Call
sas-score-find-table({ lib, name: table, server: "cas" })
- ✅ Found → confirmed
lib = lib as given, confirmed server = "cas" → go to Step 2
- ❌ Not found → call
sas-score-find-table({ lib: lib.toUpperCase(), name: table, server: "sas" })
- ✅ Found → confirmed
lib = uppercased lib, confirmed server = "sas" → go to Step 2
- ❌ Not found in either → stop. Tell the user the table was not found.
Step 2 — Read the table
Use the confirmed lib and server from Step 1. Never guess or default the server.
Use sas-score-read-table for all row reads, including filtered reads with a WHERE clause.
Use sas-score-sas-query only when the request requires SQL aggregation (COUNT, SUM, AVG, MIN, MAX), GROUP BY, JOIN, or computed columns. A WHERE clause alone is not a reason to use sas-query.
Read Table (sas-score-read-table)
When: raw rows, filtered rows, browsing — anything that is not an aggregation or join.
Parsing row count from user input:
| User says | start | limit |
|---|
| "first N rows/records" | 1 | N |
| "top N rows" | 1 | N |
| "N rows" / "N records" | 1 | N |
| "rows N to M" | N | M−N+1 |
| "starting from row N" | N | 10 |
| (not specified) | 1 | 10 |
"first" always means start at row 1 and return N rows. It is never a row offset.
Dotted format: "lib.table" → lib: "lib", table: "table" (split on first dot).
Parameters: lib, table, server (confirmed from Step 1 — required), start, limit, where
SQL Query (sas-score-sas-query)
When: COUNT/SUM/AVG/MIN/MAX, GROUP BY, JOIN across tables, or computed columns.
NOT for: simple filtered reads — use read-table with where instead.
Parameters: table (as "lib.table"), query, sql
Decision
Does the request need aggregation (COUNT/SUM/AVG/GROUP BY) or a JOIN?
YES → sas-score-sas-query
NO → sas-score-read-table (pass filter in `where` parameter if needed)
Table Name Format
- CAS:
Public.customers, Caslib.table
- SAS:
SASHELP.cars, LIBREF.table (uppercase libref)
- Dotted input
"x.y" → lib=x, table=y
Error Handling
| Error | Action |
|---|
| Table not found | Verify with find-resources first |
| Empty result | Ask user to adjust WHERE clause |
| Column not found | Ask user to verify column name (case-sensitive) |
