github.com/jdgcs/sqlite3@v1.12.1-0.20210908114423-bc5f96e4dd51/testdata/tcl/cursorhint2.test

# 2016 June 17
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library. The
# focus is on testing that cursor-hints are correct for queries
# involving LEFT JOIN.
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix cursorhint2

ifcapable !cursorhints {
  finish_test
  return
}

proc extract_hints {sql} {

  db eval "SELECT tbl_name, rootpage FROM sqlite_master where rootpage" {
    set lookup($rootpage) $tbl_name
  }

  set ret [list]
  db eval "EXPLAIN $sql" a {
    switch -- $a(opcode) {
      OpenRead {
        set csr($a(p1)) $lookup($a(p2))
      }
      CursorHint { 
        lappend ret $csr($a(p1)) $a(p4) 
      }
    }
  }

  set ret
}

proc do_extract_hints_test {tn sql ret} {
  uplevel [list do_test $tn [list extract_hints $sql] [list {*}$ret]]
}

do_execsql_test 1.0 {
  PRAGMA automatic_index = 0;
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(c, d);
  CREATE TABLE t3(e, f);
}

do_extract_hints_test 1.1 {
  SELECT * FROM t1 WHERE a=1;
} {
  t1 EQ(c0,1)
}

do_extract_hints_test 1.2 {
  SELECT * FROM t1 CROSS JOIN t2 ON (a=c) WHERE d IS NULL;
} {
  t2 {AND(ISNULL(c1),EQ(r[1],c0))}
}

do_extract_hints_test 1.3 {
  SELECT * FROM t1 LEFT JOIN t2 ON (a=c) WHERE d IS NULL;
} {
  t2 {EQ(r[2],c0)}
}

do_extract_hints_test 1.4 {
  SELECT * FROM t1 LEFT JOIN t2 ON (a=c AND a=10) WHERE d IS NULL;
} {
  t2 {AND(EQ(r[2],c0),EQ(r[3],10))}
}

do_extract_hints_test 1.5 {
  SELECT * FROM t1 CROSS JOIN t2 ON (a=c AND a=10) WHERE d IS NULL;
} {
  t1 EQ(c0,10) t2 {AND(ISNULL(c1),EQ(r[3],c0))}
}

do_extract_hints_test 1.6 {
  SELECT * FROM t1 LEFT JOIN t2 ON (a=c) LEFT JOIN t3 ON (d=f);
} {
  t2 {EQ(r[2],c0)} t3 {EQ(r[6],c1)}
}

if 0 {
  do_extract_hints_test 1.7 {
    SELECT * FROM t1 LEFT JOIN t2 ON (a=c AND d=e) LEFT JOIN t3 ON (d=f);
  } {
    t2 {EQ(r[2],c0)} t3 {AND(EQ(r[6],c0),EQ(r[7],c1))}
  }
}

#-------------------------------------------------------------------------
#
do_execsql_test 2.0 {
  CREATE TABLE x1(x, y);
  CREATE TABLE x2(a, b);
}

do_extract_hints_test 2.1 {
  SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE b IS NULL;
} {
  x2 {EQ(c0,r[2])}
}

do_extract_hints_test 2.2 {
  SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE b IS +NULL;
} {
  x2 {EQ(c0,r[2])}
}

do_extract_hints_test 2.3 {
  SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE 1 = (b IS NULL)
} {
  x2 {EQ(c0,r[2])}
}

do_extract_hints_test 2.4 {
  SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE 1 = coalesce(b, 1)
} {
  x2 {EQ(c0,r[2])}
}

do_extract_hints_test 2.5 {
  SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE 1 = coalesce(b, 1)
} {
  x2 {EQ(c0,r[2])}
}

if {0} {
  # These tests no longer work due to the LEFT-JOIN strength reduction
  # optimization
  do_extract_hints_test 2.6 {
    SELECT * FROM x1 CROSS JOIN x2 ON (a=x) WHERE 0 = (b IS NOT NULL)
  } {
    x2 {EQ(c0,r[2])}
  }
  
  do_extract_hints_test 2.7 {
    SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE 0 = (b IS NOT +NULL)
  } {
    x2 {EQ(c0,r[2])}
  }
  
  do_extract_hints_test 2.8 {
    SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE b IS NOT +NULL
  } {
    x2 {EQ(c0,r[2])}
  }
  
  do_extract_hints_test 2.9 {
    SELECT * FROM x1 LEFT JOIN x2 ON (a=x)
      WHERE CASE b WHEN 0 THEN 0 ELSE 1 END;
  } {
    x2 {EQ(c0,r[2])}
  }
  
  do_extract_hints_test 2.10 {
    SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE x2.b = 32+32
  } {
    x2 {AND(EQ(c1,ADD(32,32)),EQ(c0,r[2]))}
  }
  
  ifcapable !icu {
    # This test only works using the built-in LIKE, not the ICU LIKE extension.
    do_extract_hints_test 2.11 {
      SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE x2.b LIKE 'abc%'
    } {
      x2 {AND(expr,EQ(c0,r[2]))}
    }
  }
}
  
do_extract_hints_test 2.12 {
  SELECT * FROM x1 LEFT JOIN x2 ON (a=x) WHERE coalesce(x2.b, 1)
} {
  x2 {EQ(c0,r[2])}
}

reset_db
do_execsql_test 3.0 {
  CREATE TABLE t1 (i1 TEXT);    
  CREATE TABLE t2 (i2 TEXT UNIQUE);    
  INSERT INTO t1 VALUES('0');
  INSERT INTO t2 VALUES('0');
}

do_extract_hints_test 3.1 {
  SELECT * FROM t1 CROSS JOIN t2 WHERE (t1.i1 = t2.i2) AND t2.i2 = 1;
} {
  t1 {EQ(c0,r[1])} t2 EQ(c0,1)
}


finish_test